If the gages are not behaving properly, start by upgrading the voltage stabilizer to an IC unit.   

Clean and re-lube, or replace the speedo cable. Don't forget to lube the new one, as well.

Remove the heater control cables and lube them.  This is an unpleasant job involving spelunking up under the dash, and has most likely never been done since the car left the factory.

Bradley Restoration

Andrew Bradley, Proprietor

14093 Riverbend Rd.

Mount Vernon, WA 98273

(360) 848-6279