Hickok 600A meter replacement.
 

One each Hickok 600A tube tester with a damaged meter.
One each Simpson 100 uA taut band meter movement.

Scan the original meter face and reduce 66% to fit the
new meter face.

Put a 125 ohm resistor across the meter movement and a
130 ohm resistor in series with it.

500 uA full scale and 230 Ohm series resistance total.

Presto, a working Hickok tube tester.

Jeff