I ran across this unusual item as I was visiting Liz Stephens home last week. Liz's husband, the late Tom Stephens, was also an engineer on NKP 765. Tom picked this up from somewhere...
This is a clockwork device that still works. The gears turn and move the large silver disc with the notches in it. That disc in turn moves a spring contact that makes and breaks an electrical contact with the fixed post. The two terminals on the end of the board are for connecting this device to something external.
I have never seen this kind of a device before.