I borrowed a 10 mA 152-0140-01 tunnel diode from my 7B52, and I think I've confirmed that the only problem is the tunnel diode. Delayed triggering appears to work properly now (although I have to tweak the TD bias when switching between runs after delay, and delayed sweep triggerable). I hope that's due to my temporary TD substitution (8pF instead of 2pF).
I guess I'm in the market for a 152-0177-02 tunnel diode or two. The closest I can find is a 152-0177-01 for $20.
To sum it up, I think what happened was that CR950 shorted and was killing the sweep gate which caused the CRT to be blanked while in auto mode. When I attempted to manually pull up the sweep gate, it must have changed CR950 from a short to an open. I initially missed the fact the CR950 was open because it tests good wile in circuit, and I didn't pay close attention to the DC voltages when I was looking at the signal across it.
Thanks to everyone who took the time to help me. You saved me from countless hours of frustration.
