Does anyone know

fishy68 said
A reamer! I haven't seen any that weren't tapered. Do you have any idea what it is designed to ream? Thanks

I have seen lots of old reamers that had no taper.
Pipe possibly.
Does it have what looks like cutting ridges in it, and maybe shorter surfaces that could be for a guide of sorts?
Those tools have a kind of plumbing look to them.