I think it might be a tough one. IIRC, that's a proprietary bayonet mount. An M42 adapter might be a necessary option.
Hi John, yes it is a tough one I'm watching a 135 2.8 on the bay. waiting for a reply from the seller. I read that someone makes a M42 adapter but can't seem to find out who. I have a host of M42 takamars 24mm to 400mm. I just need the adapter.
I have a Pentamatic with 55/1.8 and 135/3.5. It took me a long time to find the
135 at a decent price. These original Yashinon-R Pentamatic mount lenses are
difficult to find. It might be easier to find a T-mount adapter for this mount.
Then you could use any of the T-mount type lenses. There was also an
adapter called the Unidapter for a line of interchangeable mount lenses by
Komura. I have one of those adapters too in that mount (but not a lens yet).
Komura lenses are excellent -- they also made lenses for Leica LTM and some
medium format lenses and teleconverters.