These cameras are so reliable you can just go on eBay and buy whatever looks nice and it will probably work fine. The only Argus C3 I have that doesn't work is a Golden Shield (I'm not risking the cosmetics to work on it ). Once you've bought a camera, if the windows are dirty, take the tip of a lens cloth and something like a qtip to clean the rangefinder and viewfinder windows and you're good to go. Rangefinder adjustment is accessible through a panel on the top.