Can a form 1 be filled out in any way with out having a passport?
If you have a Form 1 home-built suppressor and you later decide to do an improved model can you destroy the first one and build another same form and serial numbers?

You don't need a passport. You need a passport photo. In other words, the same type of photo that you can get at a drugstore that you would use to apply for a passport.

I stood in front of a white door as my wife took a picture of me on my iPhone. Attached that to my form 1 application and bingo went right on through.

How long are form 1s taking?

I would think that as far as that goes, you would probably have to keep part of the original suppressor, though I don’t know this for a fact. My reasoning is because if you have a machine gun, different animal I know, you can replace parts as it’s the receiver which is registered. I guess if you were replacing parts it seems like it would be okay.

I know that if you have a sealed suppressor, 22 LR comes to mind, the manufacturer has to cut them open but I’m not sure what their procedures are, though they are altering it. Just my opinion, I would pose that question to the ATF.

I had one approved in January; it took 5 months.