I have a friend who mentioned he had some old photo equip. his dad used at one time. Among the items was a Unicolor motorized base and a tube/drum of some sort. The base works. I thought, hmm, maybe I can do something with this to do just a couple of sheets of 4x5 at a time. I did some browsing re: Unicolor, and it appears there might be a cap or plug missing for the drum. One end has a funnel-like opening that appears to be light trapped and the other comes to a flat cone like shape with small holes in it. I'm thinking the funnel end is for filling and the other for emptying??? In any event, anyone know where I can find the cap/plug or have a suggestion for a work-around?