i deleted the other message after a few minutes realizing it wasn't TX. The lens is a soligor 35/2.8. Aperture is going in both directions. As you can see the silver ring has aperture marks but so does the ring right under it that you can't see in the picture. Hmm, I'll try to remove the mount, if I can find my fine screwdrivers...
Adapt-a-matic or similar, not adaptall. Yes, I saw a lens with a mount arrangement just like this one's this past weekend. I don't know where you'd be able to find a Pentax K or even screw mount for this.
It is the Canon FD mount. I have a Canon FD 50mm macro and a Canon Macro Lens mount Converter FD-EOS to use it on my old EOS 10s. Ironically, the only 2 Canon lenses I have for it are FD 50mm Macro and an EF 50mm Macro. I actually have the Tamron Adaptall-2 EOS-M mount and can use my SP collection with it if I were so inclined. I just realized those 2 adapters may be worth something.
It is the Canon FD mount. I have a Canon FD 50mm macro and a Canon Macro Lens mount Converter FD-EOS to use it on my old EOS 10s. Ironically, the only 2 Canon lenses I have for it are FD 50mm Macro and an EF 50mm Macro. I actually have the Tamron Adaptall-2 EOS-M mount and can use my SP collection with it if I were so inclined. I just realized those 2 adapters may be worth something.
I got thrown off by the knurled ring at the back of the lens. I've never seen that on an FD mount lens, but on the FL mount, that ring turns to lock the lens in place.
Not that it matters, it isn't a Pentax lens, and the seeler wasn't knowledgable about his wares.