This group and the following post of a bending jig come from "Machine Shop Projects" by Roy E. Knight, and published by McKnight Publishing, originally published in 1943, this second edition in 1982.
These were originally published as project manuals for machinist students in the schools. I mentioned it before and it is unfortunate, but many schools are phasing out this kind of training. I guess what the manufacturing industry needs now-a-days is code writers and programmers. The few jobs that still require "get your hands dirty" machinists have all been shipped overseas or are limited to small "design concept" or "one-of" shops.
First up is a nice depth gauge that will find lots of use in any shop.
Various lathe tooling, wood or metal turning, will benefit greatly if you can turn accurate Morse tapers such as the MT 2's used here.
A versatile V-Block and clamp is just the thing for accurate working of round stock.