I bought this last week on a local online auction. The seller said the mirror didn't work. When it arrived, I found that the mirror glass was broken, in addition to the mirror not cocking, and the camera also lacked a takeup spool - It's a bottom loader, like a Zorki or a prewar Leica. I have the instructions to replace the mirror cord - the mirror is operated by a pulley arrangement. There was a cord in the camera, which didn't look original, and was not installed correctly. I replaced it with a length of linen cord. I found a mirror in my selection of camera parts. It wasn't as deep as the original, and needed packing to match the original's thickness, but it works. I need to adjust the mirror position, though, to get correct infinity focus.