Nr 1 is a nozzle for canned air. Don't know what Nr 2 is, obviously some kind of handle. Nr 3 and 4 look like part of an old movie projector, or maybe movie camera, but most likely a projector.
#2 is a paper cutter. Handy for trimming the ragged ends of long roll background papers, etc. Just place the paper in the small notch below the "beak" and slide the whole thing across using the handle as you would expect.
"One of the greatest necessities in America is to discover creative solitude." Carl Sandburg
Yes, #2 is a cutter. It is free standing, just like an opened pair of scissors. I have no idea what the #3 is. It seems there is a slot in the middle that you can put something in there. Through the back lens, I can't see anything.
#3 reminds me of the equipment in my optometrist's office that projects the eye charts on the wall. #3 also has posts on each side which might have been for film strips containing the charts--and allow the projected ones to be easily changed when checking the patient's vision. If I am right, the piece would have been attached to a light source. My optometrist's set up reflects the projected image off a mirror onto another mirror and then onto the wall.
Nr3, maybe a device for inspecting individual frames of movie film. One end the light source the other the eyeball and the middle the film.
Could No. 3 & 4 be for showing 35mm slides and film strips with a movie projector?
That Rodenstock lens was made in 1945 or 46. It appears to be a film strip attachment for a projector. But it may not be complete. It seems to be missing the film transport knobs. It would be used in a projector vertically rather then horizontally as photographed. The film in film strip projectors ran top to bottom, Not side to side as in most slide projectors.
Who wants to have the #3? It is vintage. Good brand name!