Someone mentioned wanting a rollfilm pinhole camera. Just go to your local junk shop and buy a forty year old box camera for five euros/dollars etc, remove the lens and shutter (if there is no "B" setting) replace with a piece of foil and a home made lenscap and there it is.

Probably it will have a viewfinder too and as the pinhole to film distance is pretty much the same as it was for lens to film, then it should work adequately - bearing in mind that it wasn't perfect to begin with of course. Visualising lines from an imaginary dot in the centre of the film area, to an imaginary film-sized shape in the plane of the pinhole will work as an estimated viewfinder, or you can do the same sort of thing with a few pieces of piano-wire to make a physical peep-frame.