High volts

Well, I found parts of my overall voltage drop culprit:

overall loss from batt (+) to VR = ~1.1V key on, engine off
loss from batt (+) to firewall side of bulkhead connector ign wire = ~ 0.45V
loss from ign wire bulkhead connector to ballast resistor = > 0.5V (this concerned me-nearly half a volt just in a couple feet worth of wiring!)

I also measured loss from the inside of the cabin from the connector to the ignition switch harness

loss with old switch 0.35V~0.4V
loss with slaved in new switch 0.29V~0.31V
loss with slaved in new switch #2 0.25V~0.29V

I checked condition and loss along the battery feeds all inside the car; if there was any loss measured, it was something like 0.2mV or less. So, the physical wiring inside the car isn't bad, but the bulkhead connectors are a little loose, and the ignition switch still won't pass the 0.2V loss hurdle even if all else was well.

Granted, I didn't have the switch installed in the column at the time, and that may have something to do with it (grounding??). In any case, looks like I'll be shopping for an ignition harness before I can make any headway with it.