Sweet finds! I wonder if there is a good way to clean that moldy tape?
Of course you know, now that you have a (Quasar great) TimeMachine you gotta go back in time and bring back 3 dozen rebuilt/NOS 15GP22s from the early 60's.
I've always been into odd obsolete recording formats myself. Just this weekend I found a white wale of mine: a Playtape 2 track music cartridge player (the tapes are cassette sized 8-track like cartridges). I never thought to look on ebay for one (and often forgot the format existed), and happened to stumble on it locally...Haven't seen one in person since I was ~5-8 years old and that one was the only other one I ever saw in person...Now I just need tapes (and maybe belts)!