Fascinating ! The weird things that
happen with contacts never fail to astonish me.
I had an old Post Office key once,
which sometimes didn't make contact. The pivot was a steel taper-pin, and
it ran in the brass fixed trunnions. After a few measurement with an
Ohm-meter, I found it needed a wire
to bridge the bearing. Perhaps in Post-office service, they were
used so much that they kept up good continuity, but with me spending
perhaps an hour a day - and passing only light current, too -
it just gave up.
Thanks - 73 de Mort,