Ive recently run across this same bike in Bulgaria. I did buy it, though I'm constantly finding misinformation on it. The bike I bought is built up exactly as yours is. One difference (although it was there originally) is that the number hanger on mine was sawn off by the previous owner as well as the first undermounted toptube cable route as well as tooling marks marring up the entire groupset . I wish I could slap them hahaha.
I was wondering if you've found anything else about this bike? Why the simplex mounted mavic derailleur? Why the Miche seat post and Royale saddle? Why the 3ttt stem, modolo bars and levers? Why simplex shifters instead of a FULL mavic group?
Exact same setup as mine and two others I've found searching through... no brochure, catalogue or media showing this groupset build up this way. I think it must be a team bike build at this point.
Have you removed the bottom bracket to check that the interfacing tool was used on the BB shell to ensure the proper mounting of the mavic universal BB?