What are these and how do you use them?

When my husband's grandmother died last year, I inherited a bunch (a ton!) of different things. Most of the things are no-brainers; ribbon, fabric, beads, rickrack, etc. But there are some things that I just don't know how to use. For example, these snaps. Are there parts missing? I have lots of them but don't know how to apply them. Do I need a certain tool?

Then I have this set of tools. I think they are for setting snaps but I don't really know. They were all in a medicine bottle along with the wooden spool. It seems that she used the spool with these tools but for what? And what are those hook-things for?

Here is a close-up of the ends. They are concave to differing degrees and the male ends are different diameters.