Fuel gauge Intermittently worked,..now nothing. 66 Valiant

OK so if you're absolutely sure the pulse voltage was grounded for test ( we didn't see how/where ), and the needle doesn't move at all, that needle is stuck in place at home or separated from the bi-metal that moves it.
I've found these bi-metal strips and winding so caked with crud that it cant move ( like a plaster cast on an arm ).
The panel isn't really so difficult to R&R. the procedure is detailed in factory service manuals.
If I tried to type it all here from memory I would likely skip some step(s).