I came into possession of a Pentax Spotmatic last week. The camera seems to be in faily bad shape. The battery door is jammed, focus screen is scratched up and the camera is very very dirty, inside and out. I can deal with all of those things myself, however when examining the function of the camera itself I noticed that the mirror catches and does not flip completely to the top. I noticed that it catches on what seems to be a little switch type piece of metal on the inside of the camera. forgive my ignorance about 35mm camera but does anyone know what is going on here? Thank you in advance.