from what i can remember behind the blue door is what looked like a livingroom, and half the floor was missing

I see now my comment identifying the projector in the previous picture was not necessary LOL. Sorry....Great site, and wonderful pictures, thank you!

The projector is an "Ampro" brand 16mm sound projector. They were made from the late 1930's until the 1950's. I have one from 1942, these were common in schools, and very well built, mine still works.