And get it in writing!
The last I knew (and this is decades old, so it may have changed) the launcher is not an NFA weapon.
If it's a smoothbore tube over .50 that fires a projectile, you have an NFA item. Period
I don't think this is correct. Lots of 12ga shotguns out there that aren't!
What the ATF did back in the 1970s, (which was the last time I checked), was that they didn't consider the launcher tubes to be NFA weapons. The same went for actual artillery pieces.
Each individual round of ammo was NFA registered! Because they contain explosives. Practice rounds, with inert projectiles, were not registered.
I have seen lots of LAW tubes for sale, and once in a while bazooka type launchers, although I haven't paid much attention to them, not my thing, really.
Check with the ATF, in these matters, their word is (unfortunately) law.
Until they change it. So, best thing is get something in writing. Don't take a phone conversation with some "agent" in an office as valid. IT may be, but then again.....
Kind of like taxes, if the IRS tells you something, and it turns out to be wrong, you are still responsible!