The ATF tech branch is notorious for reversing themselves over time.
French, I know that of which you speak.
I seldom take my papered Krinkov out to the rifle range anymore if I know other folks are going to be there.
"Dude, that's illegal!" "OMG, you can't be out here with that!"
If I do take it, my paperwork accompanies me ready to retrieve - then instead of having fun shooting, I get to educate somebody on NFA SBR rules and why the gun's not illegal.
Nobody ever warned me about those people back in the day. Too bad, because it used to be one of my favorite 100 yard swinging steel target rifles. Now I just use the SLR-95 for that task.