[Milsurplus] GRC-9 receiver questions

[Hubert Miller]

 Forget the first part of my question, dial lamp position. Apparently previous user moved the socket, mayhaps to ease lamp changeout. 
I was able to reposition it using the handtools i was born with.
Now to figure out the orientation of J3 at the back of the receiver cabinet for powering up the receiver out of the cabinet. I notice that
P3  +105 volts and P6  +1.5 volts are 'mirror imaged' position relative to each other. Very funny, except potentially not. I think i'll VOM
this. The manufacturer couldn't mark the contacts?

Okay, i ohmed that out, and with only a +1.5 supply, verified with the lamp push switch that i understood the receiver plug J3 numbering.
Now to wire up some batts so i can test out the receiver. 
Looks like removing the front panel for access to the gears will not be all that difficult.
-H