Because it is a older tool made in Japan, I would guess it did not cost much at the time compared to a Starrett or Brown & Sharpe tools of the same era. I don't think a professional machinist would use it. A hobby machinist would probably use it. I would guess it would sell for maybe $25.00 to $35.00 on a good day. the only way to find out for sure it put it up for sale on eBay and see what happens. If it had been my father's or grandfather's, I would never sell it.
EvilDr235