Thank you very much for your help. Here is the circuit diagram from the manual. Does this tell the sensitivity? I appreciate your patience, as I'm a student, and probably asking really basic questions. The faceplate is fine, the plastic is cracked, so I could transfer the faceplate. I'll read up on the KM-66 to gain some insights..
-Brad
>>KM is a series originally made by Kuoritsu (I think). -66 is the width (in mm) of the face.
They can be had with a full-scale sensitivity of 50, 100, 200, 500uA, 1 & 10mA. Plus lots more. The faceplate on the PSU instrument is custom-made and says nothing about the instrument in itself, and I can't tell what kind of sensitivity it is supposed to have.
If you have the original then it can be investigated for sensitivity, & the faceplate can be transferred to the new. Search for KM-66 panel &/or instrument to learn more about it.
If you have the circuit diagram for the PSU then the sensitivity of the instrument can be deduced from that.<<