[Diverted]

Well, I fixed the problem.
YOu were on track with the tweeter field being open. Only it wasn't open; both tweeters tested fine. So I started tracing the wire from the speaker wiring harness all the way through the chassis, into each tie in point. Everything checked out OK on the first field coil. When I got to the second, one of the two field coil wires showed no continuity. The only thing thta that could be was a chafed or corroded wire. So I cut it out, removed the clamp holding the wiring bundle to the chassis and Bingo. Under the clamp, the wire was abraded in that spot and though it wasn't separated, it read open. Solder a new one to the pin, rewired, restored continuity to the tweeter field and cautiously started up the radio.
HOLY COW this radio cranks! Sounds fabulous!
Morzh, I can't thank you enough for helping me through this. It would have been a hard thing to spot if not for your guidance. I'm in your debt, and will post updates as I continue to go through the set.
Imagine that ... an abraded wire!

Ted