Rangefinder was totally out of whack, so I took the lens from the Retina II body.

The lens body was glued to the inner aluminum casing of Hexanon AR 50/1.7, which was
inserted into an adjustable spare M42 ring of M42->E mount adapter and tightly fixed.
And the whole thing was glued to L->M adapter to make M mount lens. The difficult one
is to always open in the Bulb mode without interfering with the lens' focusing movement.