Happy to help clear it up. Yeah, that's right; these tracks are not Nardini's work, and were seemingly recorded in '98. Nardini passed away in 1994, making this all the more tasteless, I think. Not that it's all that important, but I'd guess that you're probably hearing some of the same people that appear elsewhere in Desco's catalogue, for instance on "Soul Explosion" by The Daktaris. We can at least assume Martin Perna was involved. He's still around, so I'd suggest maybe contacting him if you're still curious. To be clear, I'm not suggesting the musicians are to blame or anything, this very much seems like the label owners' idea.
He's not quite really
that obscure anymore, at least by library standards. He was born Georges Achille Teperino in 1912, and was actually a childhood friend of Roger Roger. Their careers mirror each other in many ways. If you're interested I've edited a small-ish biography that can be read on
Discogs.
Here's some further reading (in French).