1964 300 Instrument Cluster Gauge Problem!

I'm thinking maybe a ground issue somewhere but thought I would ask because we are not finding any "obvious" grounding issues.

Everything was working fine until recently on this 1964 Chrysler 300. Now all the gauges slowly peg out to the right and stay there. The gauges read over charge, full and hot.

Anyone experience anything like this in any of your vehicles??
Author: E-Ticket