Looks to be in good condition, only I can't get the diopter to change when I turn the focus ring, it just seems to stay out of focus and the images don't merge. Any ideas?
Look at the base of the knurled film rewind knob to the left of the viewfinder. You should find a lever. Move it back and to until the viewfinder magnification suits your eye. Focussing a rangefinder camera is different to anything else. When you turn the lens to focus, the view in the viewfinder will not go in and out of focus like an SLR camera. Focussing is achieved by bringing the two images, visible in the viewfinder. together. When the two images coincide, the lens is focussed. If the two images do not move when you turn the focus on the lens, then I'm afraid the rangefinder may need repairing. Many people would not bother having a Zorki repaired as they are not worth a great deal, but they are great cameras to use and if you like it, it would be worth finding out about a repair. Let me know if you need any more information about how the camera works. As said previously, remember to change the shutter speed (top dial with 1 second to 1/1000 sec) ONLY AFTER THE CAMERA IS WOUND/COCKED. Otherwise, the shutter will be ruined. Also, make sure that all three black and red dots are aligned on the knob stack next to the shutter speed dial. They really are gorgeous cameras to use and additonal lenses are relatively cheap and generally good quality. Hope this is helpful.