maybe I'm just being paranoid, after hearing how quickly some of the button compasses degrade, but I'm thinking I'd give each one a check for accuracy before I added them to any kits or gear stashes.

Let me explain about the accuracy check a moment. I don't mean to compare them to another compass I think should be accurate. I mean to compare it to a known direction. Sun rises in the east and sets in the west, for my area I know which way is north, it's a fairly quick and simple thing to take each button compass and test it.