I obtained two of these military moving-vane AC voltmeters. The scale reads 0-300VAC. They are sealed and waterproof and include a synthetic rubber gasket to seal against the equipment panel. The terminal attach on the back is by solder, but you can add ring lugs and use bolts or just solder to the wires.
The advantage of the solder terminals is that the feedthrough is a hermetic glass-ceramic to metal seal, instead of the rubber or plastic seals used for most meters with bolt-type terminals.
These also have an expanded scale meaning it is not linear, so that more of the scale is used for the important readings such as 120V and 240V.
As can be seen, 60V is way down at the bottom. Also, due to the calibration, the pointer does not always rest at "0" on these.
The diameter of the body is 2.07 inches, close to the 2 1/16" (2.0625") you mention. I believe this will do fine.
I have checked this one and with 120.0 volts AC 60Hz applied, it reads best my eyes can tell 124VAC, which is 3.3% accuracy.
$10 + ship fedex ground which just covers my expense.