Other than a couple of Argus C3's, one of which was my fathers, I've never had a rangefinder. I've had loads of SLR's. The bug finally hit me over the last few weeks so I decided to test the waters with a Zorki 3C and a Zorki 4 with Jupiter 8 50mm f/2 lenses. They have not arrived yet. Both sellers were US and have 14 day hassle free return so I'm optimistic about the outcome. I've read everywhere about not changing the shutter speed on these bodies unless the shutter is cocked. Are there other things I need to be aware of or specifically look out for when they arrive?