Owning a system designed for surface to air weapon carries life imprisonment any USA, without any intent for violence, just simple possession or conspiracy to possess[]. Doesn't even matter if you have an NFA stamp, there is no exception except if it's done with authorization and behalf of the government.
Merely having a device intended to guide the rocket is also the same penalty.
Seems like the quick fix is to rebrand this from "MANPADS" to "anti-tank", right? Then it would just be a standard destructive device?