A quick trip down to my local hackerspace (SoMakeIt) to strip it and try driving the coil directly.

Turns out, it needs 48VDC directly to the coil to get full deflection on the gauge. It also consumes about 5W. It will of course consume this continuously to maintain the needle deflection.

While it's possible to drive this, it's not a simple solution, and I don't like the idea of chewing through 5W continuously.

I'm going to try stripping out the innards and using a servo motor for movement instead.