Found a few of these but don’t know what they are. Any help appreciated. The first one I see a TK. The secound one says ACO on one side and 522 on the other.
The second one is a lead bale seal. If you look around the edge of it you may see where two small wires were. I don't think the first one is a button either. It may be the end to a fuse link like the infamous "E" button that took so long to get identified.
1st=Back of a Tombac button with a steel loop missing
2nd=Looks like one that came off coveralls, without seeing the otherside
3rd/4th=Cloth seal-This button part has a flap/disc is broken off that the #2 side fits through completing the seal.