Anyone know what they are? About the same size as small coins, and several millimetres thick. I have more than this, perhaps a whole keyboard's worth, if that's indeed where they go!
Could they have something to do with IBM Selectrics / beamsprings? Because there were indeed some of those caps in the box. And the slots are similar in the rings to those in beamspring caps.
Among others.
And a bunch of Clare Pendar switches and caps I already posted.
Mysterious!