My contribution to this genre is here:
Ladies and Gentlemen, the ATAN 70-210mm one-touch zoom!
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/27977-ebay-fin...lens-what.html
(Cue the music)
Featuring a decent constant f/3.5 across the entire zoom range and multicoated optics, it's intended for Ricoh K-mount bodies, as it has the "Ricoh Pin" for auto aperture on those cameras (but doesn't have Pentax contacts), and it has the extended aperture-lever-protecting flange that prevents it from mounting unmodified on Pentax bodies. Fortunately, the flange piece just unscrewed and detached (with no apparent further effect), and the Ricoh Pin is of the rounded variety that does not tend to stick on Pentax mounts.
In any case, it's an OK lens, but I rarely reach for it.
Note the serial number: 84000031 -- probably made in 1984. I wonder how many they made. Maybe 40? It would probably be VERY VALUABLE if anybody had actually heard of it.
I put up a few pics in this followup post:
https://www.pentaxforums.com/forums/253739-post8.html
I still have no idea of its geneaology.