What are these metal guide tools?

I recently came into the possession of these 3 metal things. Can anyone tell me what these are and what they are used for?
Each have 3 holes in the bottom. One has a large round cutout in the top the with 1"-25MM on it.

The next one has two smaller round cutouts in the top with 3/4"-19MM 5/8"-16MM under the cutout.

The Last one has a large v-shaped cut out with a 90º next to the cutout.