Ok so I have searched and cannot find a description how this veglia speed works. This much I know:
1. The speedo drive spins the metal disk
2 via some magnetic magic the pie plate shaped disc on the back of the speedo needle/ mph markings rotates up to 180 degrees with the needle then pointing to the speed.
But how the two halves work together is a bit mystifying.
Anybody with understanding of how this works and why it stopped working when all looks ok?