The Asahi Pentax (AP) SLR was the first pentaprism SLR made by Asahi Pentax in 1957.
This camera was in very good external condition, however internally the shutter curtains had stuck together and were crumbling. Disassembly of the camera was quite straightforward. To get to the curtains the prism and mirror box needs to be removed too. There is a long screw under the mirror that connects to the shutter release mechanism that has to be carefully removed. This screw needs to be reinstalled back after the mirror box is removed so that the shutter can be tested successfully.
After this I removed the old curtains, measured them and cut new ones out of an old film changing bag - my favourite shutter material.
When the mirror box is reinstalled a small lever that connects the shutter curtain gears to the mirror box must be in the correct position. Part of the spring that the lever uses slots into a small hole in the camera body.
