Man, you were up and at it early this AM.
I am assuming you are saying, there was wafer section on your Tube Tester that was not being used in the circuit. If so did he switch out the two wafers, or just re-route the wiring. The fact that both red and white wires were switched over, I dont think how they were connected would matter???
Can you send/post me a copy of the Schematic you have. Do you have any idea if the actual meter is functioning properly. Also I have some suggestions on setting yourself up to test Filament, Hi-tension voltages, as well as other voltages. This would prove that your Power Transformer is working properly. Aso some good, hi-defination pics of the chassis, both from the top and bottom would help. Explain a little more fully what the switching out of the wafer/switch involved. A close-up of the said wafer/switch would maybe shed some light on the subject. Don’t let the big picture (the bowl of spagetti) get you off track. It’s not as complicated as one may think.
We may be more successful if we get into the nuts and bolts of this, using email. As we progress we could then post our successes or failures here at CVRS, for others whou may be dealing with similar Tube tester problems. Also I would say, get to know yout particular piece of test equipment as to its weak points and learn how to compensate.