I got this camera with this lens I am surprised because I was thinking that only 58mm Helios 44 was available for this camera. It seems not to be an adaptation, but I am not sure... What do you think about it please???
I'm pretty sure it's adapted, simply with adapter M39 to Start ring (was sold with Start if I remember well). Did you try to unscrew the ring?
The Mir-1 itself is nice, we don't meet that often those early Mir-1, so congratz!
If it was really factory made for Start, there should be a knop to press shutter button/close diaph (in auto mode). As far as I know, only the Helios-44 existed for Start. Princelle show also a turret, but on it are , as I believe, 2 adapted M39 lenses and an Helios-44 for start.