Now that a picture is showing, the next step is to determine what parts need to be replaced.
As a result of the previous tests, it appears obvious that probably all of the electrolytics will have to be replaced.
Random checks of some of the higher value resistors also show that many have drifted upwards in value more than 50%. Most of these are in the high voltage divider and more than likely have thrown off the deflection circuit voltages, explaining why the picture can't be centered.
There are still no clues as to why the 18 ohm resistors failed.
I wasn't about to go any further until I obtained an isolation transformer. I tried running off a 12-120V inverter (the same one I tried the first day I got the set), but now with the blown resistors replaced, the only way I could power up the set was under full voltage, variacs and inverters don't mix. So things sat while I found a good transformer.