I've seen this typ
I've not seen it in person but photos of the jaws bolted directly to the table, not on a mill but on shapers. Massive pieces of steel bolted to the table as the fixed jaw.
I was going to say years ago they made separate fixed and moveable vise jaws that were bolted to the table then the moveable jaw could be tightened against the workpiece. I suspect they would tend to slip if not bolted tight enough.
I like the pointed set screw style clamp. Let us know how your project comes out.
I've not seen it in person but photos of the jaws bolted directly to the table, not on a mill but on shapers. Massive pieces of steel bolted to the table as the fixed jaw.