Do both those 'tubes' on the top swivel? What is the height........compr
essed and extended?
I'm getting a portable music stand vibe......minus the 'plate' that would hold the sheet music and possibly have posts that would slide into those tubes.
Contruction methods (close up of screws, etc) as well as a view of the underside may help some here to date it.......whatever it is
Something along the lines of this perhaps...........