Bad temp and gas guages

[71duster06]

Were do you find replacement parts for fixing these guages. Its out of a 71' 340 Duster with the rally dash. Any help would be great!

 

[1968FormulaS340]

Normally the problem is the dash voltage regulator for the gauges.

Are the gauges damaged or just not working?

 

[71duster06]

I tested each guage individualy, and these are the only two that go not work. I just wasnt sure if there is a place to by the parts to replace the internals. Brand new ones are $100 from year one so I would like to find something a little cheaper but who knows.