SN: stamped on a trigger housing indicates a incorrectly registered conversion kit. Im not saying its wrong but something the ATF let slip by and has issues with ATF.
What would be the problem with the trigger housing being the registered component? Just curious as that is what I have.
My housing has an etched number (not stamped, semantics). The form-4 lists the manufacturer as S&S Arms Co. It's been 5 years ago now, but I had no problem with the transfer at that time.
Again, not trying to argue. Just curious.