Try an electronics supplier. There will be nothing unique about the gauge you need except its size and range.
Possible sources of replacement gauges are, among others,
http://www.allelectronics.com
http://www.mouser.com
http://www.jameco.com
http://www.electronicgoldmine.com
or even an automotive ammeter from the likes of Pep Boys.
I am trying to find a working Amp gauge for the LGB Jumbo transformer. My gauge is unresponsive, but I can measure amps from the screw/wire terminals behind the gauge. I have tried Walthers, Massoth,Silvergate (no response). I purchased the transformer on Ebay and originally both gauges were dead. Aersol contact cleaner and low air pressure blew out what looked like rusty partilces on both gauges. Thanks, Dennis
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