Hi. I inherited a beautiful Leitz Prado projector, from around 1954, for slides and microscope slides. Really good condition, and still works. Two lenses, a Leitz Wetzlar Colorplan 90mm f/2.5 and a Leitz Wetzlar Elmar 50mm f/2.8.
I called Leica and they have no ideas. Surely there's a Leica nerd somewhere who wants this! Museum suggestions? I was able to make a nice photo with it, but now it needs a good home! (I also have an old Revere 553 slide projector in original box, with 2 rectangular slide trays.)