I think you're right, Harry. These old Gem patterns do seem to be a bit overlooked by most collectors...not sure why, perhaps the lack of information on them? ...perhaps a general dislike for the type/design?...who knows!
They do have their place in airgun history though. Imagine that lad ripping open his present on xmas morning to find a Gem pattern and a packet of Lane's slugs waiting for him...gutted because he wanted one of the new fangled BSAs!...
When I was actively looking for them I tried to avoid any Gem that had been heavily restored...
I think Frank Korn had a couple nice lookers that he restored though? ..and there are others on the Gem forum too.