Speedo / Tach / Gauges: Water Temp Gauge not working

[studebro2]

62 GT dash water temp gauge does not register any temp
Replaced sending unit using copper sealant. (Avanti R1) no help
Disconnected gauge and connected to cheapo test gauge under the dash - registers temp
Called a couple Stude vendors, no one seems to have gauges.
Does anyone have experience with an aftermarket gauge that looks like it belongs, and is compatible with the engine?

[64studeavanti]

Used ones come up on ebay every once in a while. I can check about mid April to see if I have any spares. Send me pm if you still need one then.