Swap meets can work but often sellers will only offer "working"(by their definition only)cameras that, despite being intact, are really parts candidates. I've only rarely seen junk yard tables of parts only that are bagged and labeled. eBay often has tow-away junkers that can be broken down. Stuff like straps are often not worth the bother if aftermarket replacements with do even better. With 35mm manual cameras so cheap, especially somewhat off brands, is it really worth it?