[elliott]

Found it ! Its sertenly a cosina cosinon lens . Same lens shape,focusring ....reliefe

Since that one is actually a native K mount and you mention the mount is black, you'll have a problem if your body is newer than the K-7. The lens needs to short the contacts of the body, otherwise the aperture will not actually close when you take the shot. It is a common thing with Cosina lenses.

Sand the mount to bare metal where it meets the contacts of the camera.