[Phil G4SPZ]

Pete, I must congratulate you on your tenacity and fault diagnosis skills, not to mention a great write-up. I've encountered many of those faults myself, but not all together in the same set! What a horror. I wonder which fault was actually the one that caused the set to be 'retired'? Probably the lightning strike silenced it.

It's worth saying that silvered mica capacitors, once considered above suspicion, are now cropping up more and more often. The fault is usually either loss of capacitance or high internal resistance. I believe the silvering migrates away from the riveted connections after many decades.