[morzh]

>>as beautifully as only an 89-year old speaker reproducing the right audio channel will allow

I tell you this: a...let's see...89-year old speaker from the 37-116 (also, with different field coil, used in 37-690, 38-116 and 38-690), a 14" job, despite the age, will rival many a today's HiFi speakers. Which showed when I demoed my 38-690 to an unsuspecting visitor and they refused to believe that thing was built in 1938.



As for the DC volts, reading DC volts is almost like given a good first listen to "lub-dub" (aortic, pneumonic, Erbst point etc) a good doctor will always do, even if he is not a cardiologist. Basic things. Can tell a lot about the object of your research.
Voltages at the minimum will tell you:
1. If you have open circuits in RF transformers, resistor etc that connect plates to the B+.
2. Shorts (if the smoke hasn't told you so eloquently enough).
3. Wrong biases.
4. Bad parts (resistors and capacitors that leak).
5. And some other stuff.

So, yes. Go through the voltage charts and see if there are significant (not a few volts where it calls for 200V; while important, this is usually not the first thing of interest) deviations.