As I understand the rules/regulations....to possess the parts ie. trigger group etc. to allow a full auto operation it is not legal. I am sure there would be some hair splitting involved but they own the rule book so pushing the envelope on line is a fools game and a sure looser.
There is more than drilling some holes involved in this so advance at your own risk.
I don't get it, the guys got a good record on GB, so I can only imagine that greed is what's pushing him to sell this now.
I already dislike him for spamming title names. From his other auctions: "1917 Remington Mosin M91 not 91/30 m39 m44 k98". I hate when people throw in a bunch other non-relevant terms so it shows up in your searches.
EDIT:
At least the guy starts his auctions at a penny.
There is nothing illegal about this, it's a parts kit. Search "parts kit" on gun broker and you'll come up with lots of them. Most of the mp5 custom builds come from parts kits. Full auto parts are everywhere on gunbroker. Parts aren't illegal.
Anyone who builds an SBR knows you can own the upper and the lower, but it isnt a good idea to have them in the same house together until your Form 1 gets approved. I should think it unwise to have full auto machine gun parts for a gun you dont have transferred in your name.