This is for a non-working FM2 body.
I bought this on ebay in 2008 and it was working when it arrived. Shutter speeds sounded right, meter was accurate, winding worked, no problems mounting lenses. I didn't load a film and left it for a few days, then when I tried it out the mirror locked up and didn't come down. A little bit of digging online suggested a part could get stuck and removing the bottom plate would reveal the problem - I took off the plate and a small part fell out (photo below). I went no further, put the part away and left the camera.
This may be an easy fix, maybe not. The camera could be butchered for parts of sent off for a repair and CLA. Either way, I hope this is priced correctly and someone can make use of it. Cosmetically it's not too bad at all, the worse of the scuffing and scratching is on the bottom plate. The mirror is mucky and the seals could do with replacing.
I'd like to get £25 for this.