Rhodes - You are correct, the front shutter must be on T so it is open at all times when using the rear shutter. It works the other way around too. When using the front shutter, the rear shutter must be set to O. You still must remember to set the f-stop lever to shooting aperture when using either shutter. Lots to remember!
Originally Posted by Rhodes
mitch - I wonder if your camera has been repainted with black crackle paint and the original lettering has been painted over? It does sound like there may be something internal keeping the selector switch from moving. It may be fairly easy to take the cover off the side of the camera and check, but you should probably review one of the online Pacemaker repair manuals first.