You mean a Group Industries shell right. I can't imagine you mean a fully built receiver. I'm sure there's a market, though I heard some of them were out of spec (I think I actually have one of those and was planning to use it mostly as a repair section).I may be getting a few and wondered if there is any Market for them? If so, I will list them in the WTS forum. Probably $150-$175 , and they would be an FFL item
If they have a serial number on the opposite side of the receiver rear in the pictures posted I would assume they are an FFL itemOK, those are the shells, which is what I was thinking. In fact two of them don't even have the pocket to insert the trigger group pressed in yet. This is why your original post confused me a bit. So I have to ask, why are these FFL items? They're not completed receivers so they're not actual firearms. These shells usually get bought and sold by mail. Did whoever sold them to you make you go through an FFL?