The problem at this point is the only reason a suppressor needs a 4473 is the 1934 NFA designates it as a “firearm” regardless whether it is attached to a firearm. And people have “Form Oned” some quite effective suppressors made from automotive oil filters, so the “firearm” designation is absurd. And 4473s means there’s a paper trail, so they need to rescind the NFA or amend it and remove that clause.
I’m doing a bit of guessing here but it appears you still have to “Form 1” a home-made suppressor but there’s no tax. Which seems to be a disconnect because a Form 4473 is not “registration” (the dealer keeps it on file but the Feds have to track them down on a case-by-case basis, and there isn’t supposed to be a national database) but the Form 1 is a formal registration instrument. So the store-bought suppressor doesn’t get registered but the home-made one does.
Thank you for (partially) illustrating the absolute absurdity of gun control legislation. None of it serves any purpose other than annoying citizens and empowering Government Almighty.