Nikon N80 - aperture adjustment level got bent to heck so everything was dark all the time and the preview button didn't work. Figured out what it was and did some bending to get it back inline. Don't know if it's perfectly lined up but seems to work just fine. Lenses seem to open the same amount on and off the body.
Kodak Automatic 35 - asa selection know would not turn at all. Applied a bit of machine oil and let it sit for a few hours. Still hard to turn but after a few movements back and forth with a plier it now move smoothly. Also note this is a very small know that is a bit problematic for my aging fingers to start with.
I have a few more that I'm going to atttempt to fix. Have an Argus C20 that has the focus portion of the lens assembly frozen solid. Thinking about loosening some screws and applying a bit of oil to the mechanism. Don't want to disassemble the whole lens/viewfinder mechanism if I can avoid it.
Have an Argus Argoflex 75 that the focus lens has broken out. Will attempt to reattach it and see what happens.
I want the Argus 75 and C3 in great working order someday. These were the first cameras I can ever remember using. My Mom was the family archivist and those models were her cameras.