[pokey]

Thank you, rfeenstra.  By not being able to test it, I meant I don't know what I'm doing.  Today I used a multimeter for the first time ever (to see which tubes might be okay).

Would you mind walking me through how I take the measurements you mentioned with the meter?  I see in the schematic yellow and green going from the secondary to the rectifier, but when I look under the chassis I don't know where to apply the probes.  Please assume near-zero experience on my part, so if you're up to it, the "for dummies" version will be immensely appreciated!