That is neat!
It does indeed appear to be an upside down Royal 501 Prince hand vac. The first thing I thought of when I saw your picture is the old Hoover bag cleaning machine(s), but cleaning erasers seems like a more likely intended use for this gadget given its smaller size and its residence in an old school.
Not sure why you don't want to keep it. It sure is a neat artifact. I've never seen/heard of this setup before, but maybe that just the limit of my knowledge. Nevertheless, I would hate to see it get trashed. I'm sure a collector here would like to have it if you don't.
broomvac