That tape came from me... I found it in the collection of an engineer who worked on a ton of Heuy Meaux productions.
I have an acetate with those two songs that I had posted about on the old G45 forum... It turned out the backing track was used in a Trashmen song, I believe...
Not sure what the story on that was, but it wasn't uncommon with Meaux productions to reuse the same music for different releases.
I bought that tape amongst a couple hundred others which I sold for a token fee to a friend of mine who ran a reissue label, and he later put some of them on ebay.