Check here for Simpson information & schematics.
http://bama.sbc.edu/simpson.htm
Norm
:Recently given an old simpson 260. Only number on face is 5991 MO. Has 1.5V and what appear to be 4 AA batteries. Unfortunately they leaked throughout meter. Have got cleaned up but in the process a few wires broke off there connections. Anybody know what I might have and possibly a wiring diagram or schematic. No fuses mostly wirewound resistors. Would like to restore as a retirement project.
:Thanks