Revcounter modification.
If you revcounter has broken down due to mechanical reasons you may consider modifying to electronic solutions.
When I modified my MG VA to a modern engine I lost the dynamodrive for my tacho so had to look for other ways of getting the required info to let my revcounter register.
The inside mechanism was removed (and stored for later use) and replaced by a modern electronic revcounter mechanism.
This is how it looks:
The set up is insulated in such a way that minus or positive to earth does not matter.
The three wires are connected as follows: red to positive 12V, blue to earth 12 V, yellow in parralel to the CB side of the coil.
Modification carried out by: Van Putten & Son, Clocks and Instruments from Rotterdam, Holland.