I started collecting those libraries. Most are in FLAC but some are in mp3's and AAC.
You can find me on Soulseek. ( my user name is martel8000, send me a message and I'll add you as a trusted buddies )
Here's the list of the title I was able to grab (and is available for download on Soulseek):
  170&151 - Showcase Production Music
  CC-823 - Instant Library Service
  CC-824 - Instant Library Service
  CK-737 - Instant Library Service
  CK-753  (aac)
  CK-756 - Instant Library Service
  CK-763 - Instant Library Service
  CK-764 - Instant Library Service
  CK-766 - Instant Library Service
  Country and Western 4000 
  Country and Western 4009 
  Country and Western 4010 
  Country and Western 4019 
  Country and Western 4105 - 1972 
  Country and Western 4118 
  Country and Western 4311 
  Country and Western 4400 
  Country and Western 4500 
  Country and Western 4501 
  Country and Western 4503 
  Country and Western 4504 
  Country and Western 4604 
  Creative Sales Service 5002 (1963) 
  Creative Sales Service 5003 (1963) 
  Creative Sales Service 5011 
  Creative Sales Service 5014 
  Creative Sales Service 5018 
  Creative Sales Service 5026 
  Creative Sales Service 5103 (1963) 
  Creative Sales Service 5112 
  Creative Sales Service 5120 
  Creative Sales Service 5122 
  Creative Sales Service 5206 (1963) 
  Creative Sales Service 5207 (1964) 
  Creative Sales Service 5208 
  Creative Sales Service 5224 
  Creative Sales Service 5236 
  Creative Sales Service 5320 
  Creative Sales Service 5908 
  Creative Sales Service-key Series - 5004 
  Creative Sales Service-key Series - 5043 - Specific Businesses  
  Creative Sales Service-key Series - 5229  
  Creative Sales Service-key Series - 5402  
  Creative Sales Service-key Series - 5829  
  Director Series - Disc 01  
  Director Series - Disc 02  
  Director Series - Disc 07
  Director Series - Disc 24 - Rhythm & Synthesizer (1985)
  Director Series - Disc 50 
  Image 45 D3 
  Image 45 D4 
  Image 45 D5 
  Instant Library Service - CC-813 - Concept Commercials
  Instant Library Service - CC-815 - Concept Commercials
  Instant Library Service - CC-816 - Concept Commercials
  Instant Replay - 821 - Commercial Concepts  
  Instant Replay - 828 - Commercial Concepts  
  Instant Replay - 920 - Sales & Holidays  
  Instant Replay - 931 - Sales & Holidays  
  Instant Replay - Mb 1234 - Music Beds  
  Library Demo Tapes 
  MS 415 - Instant Replay - Synthesizers & Brass (1980)
  New TTS - 3024 - Unknown Artist - Business Commercials - 19xx (WAV) - CDUW Dig 00265
  New TTS - 3025 - Unknown Artist - Business Commercials - 19xx (WAV) - CDUW Dig 00266
  New TTS - 3026 - Unknown Artist - Business Commercials - 19xx (WAV) - CDUW Dig 00267
  New TTS - 3028 - Unknown Artist - Business Commercials - 19xx (WAV) - CDUW Dig 00268
  New TTS - 3029 - Unknown Artist - Business Commercials - 19xx (WAV) - CDUW Dig 00269
  New TTS - 3033 - Unknown Artist - Specific Businesses - 19xx (WAV) - CDUW Dig 00270
  New TTS - 3034 - Unknown Artist - Specific Businesses - 19xx (WAV) - CDUW Dig 00271
  New TTS - 3040 - Unknown Artist - Specific Businesses & Production Music Tracks - 19xx (WAV) - CDUW Dig 00272
  New TTS - 3041 - Unknown Artist - Specific Businesses - 19xx (WAV) - CDUW Dig 00273
  New TTS - 3136 
  New TTS - 3228 - Unknown Artist - Images - 19xx (WAV) - CDUW Dig 00274
  New TTS - 3237 - Selling Images; Images
  New TTS - 3239 - Unknown Artist - Images - 19xx (WAV) - CDUW Dig 00275
  New TTS - 3245 - Selling Images; Images
  New TTS - 3246 - Selling Images; Images
  New TTS - 3250 - Selling Images; Images
  New TTS - 3251 - Selling Images; Images
  New TTS - 3253 - Images; Production Music Tracks
  New TTS - 3256 (1988) 
  New TTS - 3311 - Unknown Artist - Specific Sales - 19xx (WAV) - CDUW Dig 00276
  New TTS - 3312 - Unknown Artist - Special Sales - 19xx (WAV) - CDUW Dig 00148
  New TTS - 3316 - Unknown Artist - Special Sales - 19xx (WAV) - CDUW Dig 00277
  New TTS - 3317 - Unknown Artist - Sales & Holidays - 19xx (WAV) - CDUW Dig 00278
  New TTS - 3328
  New TTS - 3410 - Unknown Artist - Musical Christmas Cards - 19xx (WAV) - CDUW Dig 00279
  New TTS - 3413 - Unknown Artist - Business Holiday Greetings - 19xx (WAV) - CDUW Dig 00280
  New TTS - 3415 - Unknown Artist - Horn Of Plenty Days & Tourist Images - 19xx (WAV) - CDUW Dig 00281
  New TTS - 3416 - Unknown Artist - Musical Christmas Cards - 19xx (WAV) - CDUW Dig 00282
  New TTS - 3417 - Unknown Artist - Christmas Images - 19xx (WAV) - CDUW Dig 00283
  New TTS - 3422 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3423 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3426 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3427 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3428 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3429 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3431 - Unknown Artist - Sales & Holidays - 19xx (FLAC)
  New TTS - 3435 - Sales & Holidays
  New TTS - 3438 - Sales & Holidays
  New TTS - 3440 - Sales & Holidays (Christmas Images)
  New TTS - 3442 - Sales & Holidays
  New TTS - 3444 (1988) 
  New TTS - 3506 - Singing Deejay Intros; Impact Accents
  New TTS - 3703 - Unknown Artist - Impact Accents - 19xx (FLAC)
  New TTS - 3807 - Unknown Artist - Station Features & Electronic News Effects - 19xx (FLAC)
  New TTS - 3808 - Unknown Artist - Patriotic Promos - 19xx (FLAC)
  New TTS - 3809 - Unknown Artist - Station Features - 19xx (WAV) - CDUW Dig 00294
  New TTS - 3811 - Unknown Artist - Work Parts - 19xx (WAV) - CDUW Dig 00295
  New TTS - 3812 - Unknown Artist - Work Parts - 19xx (WAV) - CDUW Dig 00149
  New TTS - 3813 - Unknown Artist - Work Parts - 19xx (WAV) - CDUW Dig 00296
  New TTS - 3814 - Unknown Artist - Production Music Tracks - 19xx (WAV) - CDUW Dig 00150
  New TTS - 3815 - Unknown Artist - Production Music Tracks - 19xx (WAV) - CDUW Dig 00297
  New TTS - 3816 - Unknown Artist - Work Parts - 19xx (WAV) - CDUW Dig 00151
  New TTS - 3817 - Unknown Artist - Production Music Tracks & Work Parts - 19xx (WAV) - CDUW Dig 00152
  New TTS - 3819 - Unknown Artist - Production Music Tracks - 19xx (WAV) - CDUW Dig 00298
  New TTS - 3823 - Work Parts
  New TTS - 3825 - Station Features;Station Programming Beds
  New TTS - 3901 - Unknown Artist - Electro-Music Logos - 19xx (WAV) - CDUW Dig 00153
  New TTS - 3908 - Electro-Music Logos; Deejay Promos
  PM-61
  PM-77
  SOB 6015  [ADPCM]
  SOB 6029-6064 
  SOB 6057 
  SOB 6075 
  SOB 6102 
  SOB 6162 - Sounds Of Broadcasting
  SPM 001 - Showcase Production Music
  SPM 001 Wwp  
  SPM 002 - Showcase Production Music
  SPM 002 Wwp  
  SPM 003 - Showcase Production Music
  SPM 003 - WWP 
  SPM 004 - Showcase Production Music
  SPM 004 - WWP 
  SPM 005 - Showcase Production Music
  SPM 005 - WWP 
  SPM 006 - Showcase Production Music
  SPM 006 - WWP 
  SPM 007 - Showcase Production Music
  SPM 007 - WWP 
  SPM 008 - Showcase Production Music
  SPM 008 - WWP 
  SPM 009 - Showcase Production Music
  SPM 009 - WWP 
  SPM 010 Wwp  
  SPM 011 - Showcase Production Music
  SPM 013 - Showcase Production Music
  SPM 014 - Showcase Production Music
  SPM 015 - Showcase Production Music
  SPM 016 - Showcase Production Music
  SPM 017 - Showcase Production Music
  SPM 019 - Showcase Production Music
  SPM 021 - Showcase Production Music
  SPM 022 - Showcase Production Music
  SPM 026 - Showcase Production Music
  SPM 028 - Showcase Production Music
  SPM 078 - Showcase Production Music
  SPM 101 - Showcase Production Music
  SPM 102 - Showcase Production Music
  SPM 103 - Showcase Production Music
  SPM 104 - Showcase Production Music
  SPM 105 - Showcase Production Music
  SPM 106 - Showcase Production Music
  SPM 107 - Showcase Production Music
  SPM 108 - Showcase Production Music
  SPM 109 - Showcase Production Music
  SPM 116 - Showcase Production Music
  SPM 117 - Showcase Production Music
  SPM 119 - Showcase Production Music
  SPM 124 - Showcase Production Music
  SPM 128 - Showcase Production Music
  SPM 130 - Showcase Production Music
  SPM 136 - Showcase Production Music 
  SPM 139
  SPM 146 - Showcase Production Music
  SPM 147 - Music Trax
  SPM 151 + 170
  SPM 162
  SPM 164 - Showcase Production Music
  SPM 168  (X-mas) (different rip)
  SPM 168 
  SPM 174 - Showcase Production Music
  SPM 179 - Showcase Production Music 
  SPM 184 - Showcase Production Music
  SPM 185 - Showcase Production Music
  SPM 186 - Showcase Production Music
  SPM 187 - Showcase Production Music
  SPM 187 - Showcase Production Music (different rip)
  SPM 188 - Showcase Production Music
  SPM 189 - Showcase Production Music
  SPM 190 - Showcase Production Music
  SPM 191 - Showcase Production Music
  SPM 193 - Showcase Production Music
  SPM 194
  SPM 194 - Showcase Production Music
  SPM 195 - Showcase Production Music
  SPM 195 [320]
  SPM 196 [320]
  SPM 197 [320]
  SPM 198 - Showcase Production Music
  SPM 198 - Showcase Production Music (198x)
  SPM 199 - Showcase Production Music
  SPM 199 [320]
  SPM 200 - Showcase Production Music
  SPM 200 [320]
  SPM 201 [320]
  SPM 202 - Showcase Production Music
  SPM 202 [320]
  SPM 203 [320]
  SPM 204 - Showcase Production Music (Christmas)
  SPM 204 [320]
  SPM 205 [320]
  SPM 206 - Showcase Production Music
  SPM 206 [320]
  SPM 207 [320]
  SPM 208 [320]
  SPM 209 [320]
  SPM 210 - Showcase Production Music
  SPM 210 [320]
  SPM 211 - Showcase Production Music
  SPM 211 [320]
  SPM 212 [320]
  SPM 213 - Showcase Production Music
  SPM 214 - Showcase Production Music (Christmas)
  SPM 214 [320]
  SPM 215 - Showcase Production Music
  SPM 215 [320]
  SPM 216 - Showcase Production Music (Christmas)
  SPM 216 [320]
  SPM 217 [320]
  SPM 218 [320]
  SPM 219 [320]
  SPM 220 [320]
  SPM 227 - Showcase Production Music (1985 - 6)
  SPM 228 - Showcase Production Music (Christmas)
  SPM 230 - Showcase Production Music
  SPM 238 - Showcase Production Music
  SPM 240 - Showcase Production Music - Christmas
  SPM 241 - Showcase Production Music
  Tanner Saturday Night
  Tanner Total Sound - 3426S  
  The CAT 7001 [FLAC]
  The CAT 7003 
  The CAT 7013 - Custom Audio Tracks - Creative Advertising Thematics
  The CAT 7016  
  The CAT 7033
  The CAT 7088
  The CAT 7112 
  The CAT 7136 
  The Key Series 5056 
  The Key Series 5057 
  Thunder Country - 4132 - Brand Names  
  Thunder Country - 4210 - Holiday Productions 
  Trendsetter Vol. 2 - 23
  Trendsetter Vol. 2 - T-1
  Trendsetter Vol. 2 - T-3
  Trendsetter Vol. 2 - T-4
  Trendsetter Vol. 2 - T-10
  TRS - Volume 1 Disc 1 - Trendsetter
  TRS - Volume 1 Disc 10 - Trendsetter
  TRS - Volume 1 Disc 11 - Trendsetter
  TRS - Volume 1 Disc 12 - Trendsetter
  TRS - Volume 1 Disc 13 - Trendsetter
  TRS - Volume 1 Disc 14 - Trendsetter
  TRS - Volume 1 Disc 16 - Trendsetter
  TRS - Volume 1 Disc 17 - Trendsetter
  TRS - Volume 1 Disc 19 - Trendsetter
  TRS - Volume 1 Disc 2 - Trendsetter
  TRS - Volume 1 Disc 20 - Trendsetter
  TRS - Volume 1 Disc 21 - Trendsetter
  TRS - Volume 1 Disc 22 - Trendsetter
  TRS - Volume 1 Disc 26 - Trendsetter
  TRS - Volume 1 Disc 28 - Trendsetter
  TRS - Volume 1 Disc 3 - Trendsetter
  TRS - Volume 1 Disc 32 - Trendsetter
  TRS - Volume 1 Disc 33 - Trendsetter
  TRS - Volume 1 Disc 34 - Trendsetter
  TRS - Volume 1 Disc 35 - Trendsetter
  TRS - Volume 1 Disc 36 - Trendsetter
  TRS - Volume 1 Disc 37 - Trendsetter
  TRS - Volume 1 Disc 38 - Trendsetter
  TRS - Volume 1 Disc 39 - Trendsetter
  TRS - Volume 1 Disc 4 - Trendsetter
  TRS - Volume 1 Disc 40 - Trendsetter
  TRS - Volume 1 Disc 41 - Trendsetter
  TRS - Volume 1 Disc 42 - Trendsetter
  TRS - Volume 1 Disc 43 - Trendsetter
  TRS - Volume 1 Disc 44 - Trendsetter
  TRS - Volume 1 Disc 45 - Trendsetter
  TRS - Volume 1 Disc 46 - Trendsetter
  TRS - Volume 1 Disc 47 - Trendsetter
  TRS - Volume 1 Disc 48 - Trendsetter
  TRS - Volume 1 Disc 49 - Trendsetter
  TRS - Volume 1 Disc 5 - Trendsetter
  TRS - Volume 1 Disc 50 - Trendsetter
  TRS - Volume 1 Disc 53 - Trendsetter
  TRS - Volume 1 Disc 59 - Trendsetter
  TRS - Volume 1 Disc 60 - Trendsetter
  TRS - Volume 1 Disc 61 - Trendsetter
  TRS - Volume 1 Disc 62 - Trendsetter
  TRS - Volume 1 Disc 64 - Trendsetter
  TRS - Volume 1 Disc 7 - Trendsetter
  TRS - Volume 1 Disc 8 - Trendsetter
  TRS - Volume 1 Disc 9 - Trendsetter
  TRS - Volume 2 Disc 5  - Trendsetter
  TRS - Volume A Disc 24 - Trendsetter
  TRS - Volume A Disc 25 - Trendsetter
  TRS - Volume A Disc 28 - Trendsetter
  TRS - Volume A Disc 3 - Trendsetter
  TRS - Volume A Disc 31 - Trendsetter
  TRS - Volume A Disc 32 - Trendsetter
  TRS - Volume A Disc 33 - Trendsetter
  TRS - Volume A Disc 34 - Trendsetter
  TRS - Volume A Disc 35 - Trendsetter
  TRS - Volume A Disc 4 - Trendsetter
  TRS - Volume A Disc 6 - Trendsetter
  TRS - Volume A Disc 7 - Trendsetter
  TRS - Volume A Disc 8 - Trendsetter
  TRS - Volume A Disc 9 - Trendsetter
  TRS - Volume B Disc 8 - Trendsetter
  TRS V-1-D12 - Trendsetter
  TRS V2 D05 - Volume 2 disc 5
  TRS Volume 2 Disc 05 - Trendsetter
  TRS Volume 2 Disc 23 - Trendsetter
  TTS 3000-D - (Audition record) 
  TTS 3001 
  TTS 3007 
  TTS 3202 
  TTS 3215 
  TTS 3217 
  TTS 3218S 
  TTS 3313 
  TTS 3314 
  TTS 3315 
  TTS 3403 
  TTS 3416 
  TTS 3501 
  TTS 3504 
  TTS 3802 
  TTS 3804M
  TTS 3909 
  TTS 3910 
  TVS 01 
  TVS 04
  TVS 11
  TVS 12
  TVS 13
  TVS 14
  TVS 15
  TVS 21
  TVS 25
  TVS 25 
  TVS 30
  TVS 31
  TVS 33
  TVS 34 
  TVS 35
  TVS 40 
  TVS 42   (X-mas)
  BN-632 - Instant Library Service
  CC-822 - Instant Library Service
----------------------------------------------------------------------------------------------
Would love to complete the whole collection but there's hundreds of titles missing so anything anyone can add, I would really appreciate.As a reference, here's a list that I am aware of:
https://librarymusicthemes.com/index.php?topic=1913.msg11510Thanks to @Killa-The-Librarian and @Mr for listing those.
Best