Yes, good detective work, I'll start putting money on it being a Follis, and since it has a DO hanger for a Campy rear derailleur (rather than a Simplex or Huret) something like that model 472 is very likely, too. I had an older Follis years back that had great pierced head lugs similar to this one, below. I sold it on cause it was too big for me, but was impressed with the quality and details (compared to some of the more commonly-known French makes). photo is courtesy of Wool Jersey Gallery and provided by Uwe Just of his 1951 Follis, thanks Uwe!