I made the bench vice like yours in the apprentice skool in about 1973 or 1974. It was something of a community effort as the screw was turned by one chap as part of a batch on the capstan lathe. Somebody else made the serrated jaws on the shaper. The main parts were chewed out of chunks of mild steel on the vertical milling machine. There were tight tolerances to work to with measuring rods over the angled faces to achieve a decent shake-free fit of the moving jaw on the base.
I no longer have it as I thought it very limited, but my sister has one that my wife, then a commercial apprentice, made in the same place – which was where we met!
I’m fairly sure it would have been to Imperial measurements. It shouldn’t be too hard to measure yours up!