Nice score Whartung. Got mine when I bought the three volumes of reprints from FFE some time back. I know, its a reprint, but its in dead tree and I got them ALL!!!
Yea, I have the whole set, all originals. They're in a plastic crate -- somewhere (I think the garage, not sure though).
I recall my LGS having lots of them, just languishing, so I went in one day and bought one of each that they had remaining. I got, like, 8 of them. They had them for quite a while.
It's curious -- since learning indirectly the "intricate details" of the gaming business from the closing of GDW, notably that games can't be returned but books can, it was curious that they kept these things. I wonder if they could not send them back for credit (because they were "games" and not "books"), or simply chose not too. Challenge was most definitely a magazine, and magazines get returned (a good magazine has a 65+% return rate -- crazy I know. A GREAT magazine has 50%). So I dunno if the JTAS was some middle limbo, or simply that's how they were negotiated with the game dealers.
One of the notable things about this store was they had these bins stuffed with old adventures and modules from all sorts of games. They just lived there, you would thumb through them as you like, they didn't take up a lot shelf space. The JTAS were not in that bin (since they really didn't fit the format), but those bins were pretty much where Old Game Stuff when to die and absorb dust.