Ted my knowledge of French guns is limited so I bow down to your superior knowledge on this . I have however seen many French made guns with NO original French proof marks .To say no Frenchman would buy an unproofed gun is however a bold statement . I doubt very much if any Frenchman or any other European in the late 1800's or early 1900's even gave proof a thought.
After all many Americans bought US made guns that had no recognised proof marks of any kind .