old adjustable exam stool from a Doctor's office?

This little heavy-ish 4-legged iron/steel stool looks like it might have originally served in a Doctor's office or somesuch. (?) Now with a few coats of white paint on it, there *might* be the remains (at least) of a baked enamel finish underneath. Its round seat is a little over a foot across, and screws up and down to make it roughly 20 - 25" high.

It came out of Mom's basement, but I don't have the slightest idea how (and when) it came to get there -- I don't have any recollection of it around our house when I was growing up, so have to guess she might have found it somewhere around the farm when they first bought the property.

Likewise I have no real idea of how old it is or who might have manufactured it, there are no markings on it unless they're totally obscured by the layers of paint.