Gibson G-3/Grabber

Saw one today in a store was priced at 500 UK pounds. On the neck there is like a slight gap where it connects to the body like on the side, its only like 1mm and also the cut of the body where the neck fits seems a little shoddy, it seemed to play good and the neck is nice and straight, but this raised a few red flags for me. I just wanted to know if this is common? or could it have had a replacement neck etc? though the neck on there seemed original.
Despite this i offered the guy 450 cash and he wouldnt take it, and was abit of a prick so i walked out.