Razocaine, for rollfilm you can find any cheap, non-working, 1950's 120 camera and remove the bellows and door to turn it into an economical 'rollfilm-back'. With a bit of ingenuity a self-made foamcore pinhole-turret on the front could even be removable, allowing for alternative view angles, then use the window on the back of the modified body and the winder on top to wind-on the film in the usual way.