What is this vise or holder?

Question

This turned up in cleaning up the shop.

There's a base bar with three attachments. First a round bolt of adjustable angle, the pivot has angle markings "88, 68, 59, 49, CSK". The other two form an axis and have an angled bed as if for something round. One attachment screws down to clamp what's held. The other pushes a base plate along the bed axis. There's also a little plate on the front, able to stick up into the bed's path but without quick adjustment by hand screw.

I'm thinking it's more likely to hold a tool than a workpiece, perhaps knives for turning? What are those funny angle numbers?

Update

There's this other item, a disc cutter for short pieces. It shows the same colors though I don't see where the first thing would be mounted, so it might be a red herring.

Answer 1

The machine is a miter saw, and appears to be unrelated to the first tool: https://www.proxxon.com/en/micromot/27150.php.

The first thing is probably a holding guide for sharpening drill bits (image source: https://dengarden.com/home-improvement/drill-sharpener):

There should be a base where the cylindrical rod goes in. It allows to position a drill with a fixed angle and rotation next to a bench grinder.