Olga
Like Gary, I have never run across a vacuum like that until yours, so as far as knowing anything about it, I have nothing to contribute, however that is a VERY impressive vacuum, and you have indeed taken excellent care of it! Most vacuums 70+ years old, even if stored properly and taken good care of, don't have the shine your machine has. Is the hose original to it as well?
You have a beautiful vintage vacuum and I really hope you find out some information on it, as I'm rather curious about it now myself!