Don, as suggested above, the reason the wood doesn't match the lack of engraving is that the wood isn't original. Total restocking job. Looks to be quite well done, but no way is it the original French wood.

French shotguns are pretty hard to date. Unlike some other national proofhouses, the French didn't use date codes. Proofed with PT powder, 2 1/2" chambers . . . I think a pretty good guess would be a between the wars gun. 1920-40 or so. Might be newer than that; not likely older.