[DaleHCook]

6 - For the internal wiring that ultimately needs replacing, what specs should I be looking for in a replacement?

The replacement wire per se has been addressed well upstream. I try to stock both solid and stranded wire in all ten RMA colors, in gauges from 26 to 18.

My caution is to replace only one wire at a time. Take plenty of photos so that a replacement wire can be dressed (aka routed or located) exactly as the original was dressed. Proper wire dress can be important in some circuits.

I went through and tested the resistors...

Did you do so with the resistors in-circuit or out-of-circuit? Testing in-circuit can result in measurements which are too low because of connections to parallel resistances. However, any resistor which measures too high in-circuit is almost certainly bad. I prefer to test all componrnts out-of-circuit by disconnecting one end, and then testing with a quality LCR meter (I own a DER EE DE-5000).