How about some official library merch?
Found on eBay:
A used Warner/Chappell Production Music cap:
hxxps://www.ebay.com/itm/186613393423

- a matching used Universal Production Music cap:
hxxps://www.ebay.com/itm/204889190709

or perhaps an APM Music cap?
hxxps://www.ebay.com/itm/196243334392

Also some vintage tees:
Firstcom Broadcast Services:
hxxps://www.ebay.com/itm/116079647358

Megatrax Impact Trailers 2:
hxxps://www.ebay.com/itm/166310803679

Killer Tracks "Video Game Music":
hxxps://www.ebay.com/itm/325410104192

Mexican Music Library (Firstcom):
hxxps://www.ebay.com/itm/165226970767

Chicago Music Library:
hxxps://www.ebay.com/itm/275915159948
