66 Cuda Temp gauge issues

Last panel I serviced was a 66 B'cuda with nearly the same problem.
The mounting and contact studs on the gauges are swedged into a piece of fiber board. That board slowly hardens, distorts, or gets water damage, whatever. Tightening the nuts will eventually separate the stud from the board and ruin the internal workings of any gauge.
You really cant blame someone who went in there to replace bulbs if and when other 45 year old stuff falls apart.