would be better to ask on a french poultry forum as France has several breeds USA either doesn't have or only a very few.
also a lot of people on here try to guess based on what is common in USA so you probably will get a lot of not very likely guesses.
My own not very likely to be correct guesses would be basque(think they have yellow legs though?) or Marans or French version of production bred hybrids.
anyways hope someone from France can pipe up here....