Ricoh Auto Rikenon 55mm f1.4 M42 Screw Mount Prime Lens -Bargain, As is-
This is a beautiful standard lens with an M42 screw mount. This would be an excellent lens on a classic M42 kit or adapted to mirrorless.
You should look up some sample images taken with this lens, I think that you'll be impressed. It has a very dreamy quality to it.
This one is in good condition except that there are a series of light marks in the coating on the front and rear elements. I can only see them with a flashlight but they may soften your images very slightly when shooting in harsh conditions. Otherwise the glass is clean with no haze or fungus. The aperture does not re-open quickly when shooting on "A". There isn't oil on the blades but the pin system may need to be cleaned for the "A" functionality to work smoothly. "M" works perfectly. The focus is smooth.