"You show what seems to be genuine concern for the poster, but it's eh for the buyer..."
Buyers need to look out for themselves. There are plenty of legal SBR owners, new guys submitting Form 1's, guys who want to thread for a legal SBR/suppressor combo, etc.
The "illegals" are probably outnumbered by the legals. SBR's (and suppressors) are getting as common as single shot .22's in my neck of the woods. Can't go to the range without seeing them now. They don't even attract a look.
Caveat Emptor... that's BUYER beware.