Gauge restoration

I am planning to redo my gauge cluster shortly. I have found someone to do the plating and painting of the trim. I am also looking to have someone to go through the ralley dash gauges to ensure they are ready for another 40 years. Any recommendatins out there to have the speedo and tach looked at? I amy also consider changing the ammeter to a volt meter and eliminate the high current through the firewall . Any recommendations on volt meter conversions? Also has anyone changed the tach to a more modern electronic type? I remember seeing this option available somewhere.

Thanks