It seems to me its some kind of hose clamp. Murray makes clamps but I don't see anything that would work for this. The vise appears to be made of bronze. The die is 1" diameter and about 1-1/8" at the recess. Bench mount and can swivel. Any ideas.

Looks like a hydraulic hose fitting crimper. You would have a set of different size dies to fit it.


EDIT:  I had the right idea, according to a google search for Murray Hose Crimper, it is an AC line crimper and had several die sets with it.

Thank you Papa. That was quick. I found this https://www.atcoproductsinc.com/wp-content/uploads/3300_instruction.pdf  I only have the #12 die.