I found the schematic and scanned it. PM me with your email address if you want it.
It's a 3MB zip file.
The meters are: (1) 0-100ma DC (2) 0-1ma DC (3) 0-1ma DC (4) 0-1ma DC (5) 0-15v AC.
The voltage control is a little less obvious. These are bad xeroxes of hand drawn schematics, and there are some inconsistencies.The only likely suspect on the parts list is a "25 ohm 1 amp ohmite".
John