Thanks for the encouragement.
The face of the meter reads in very small letters at the bottom of the face:
CT ratio 240/1
Type A-25
Style PA -70907-E
F.S. = 5 amp

 

I was just digging through my bin of "panel devices" and found 4 vintage yokogawa panel meters with a full scale deflection at 95microAmps. Even with external ~35k of shunt resistance attached, my dmm drove it to half scale. With out that shunt resistance i suspect i could have damaged the movement.

Interesting. Good to know.

 

Thanks for the encouragement.
The face of the meter reads in very small letters at the bottom of the face:
CT ratio 240/1
Type A-25
Style PA -70907-E
F.S. = 5 amp

You've just answered a bunch of your questions.

Can you open up the meter to get at the internals without damaging it? I suspect that you can for a meter that old. If you can get at the secondary side of the CT then you have already made the problem a lot more tractable. There is almost certainly a shunt resistor in there and by replacing it with a larger valued resistor you can get the current that you need to drive it down to something a small circuit can handle. The meter will probably respond to DC current and the calibration is irrelevant since you simply want it to indicate something. The meter may or may not be full wave rectified, so you might need to try apply the DC current in both directions.