I don’t believe proof was actually compulsory in France. However, and this is important, IT MAY AS WELL HAVE BEEN.

Every catalog makes mention of proof, and gunmakers paid for varying levels of proof on their wares. There was a major overhaul of the rules of proof in 1923. To a very large degree, most of the gunmakers in France were mom and pop shops, and proofing themselves would not have been an option. Manufrance could sell you a gun, a case, a bicycle or a car to carry it in, a tent to use at your hunting camp, hunting clothes, and a sewing machine to repair them. And lots of other household items.

They were huge.

Best,
Ted