[jerryhawthorne]

Morzh is dead on. Perhaps easier as I suggested earlier is to pull the dang tube and check again the resistance from the + of the first cap to ground. If it goes really high, the tube is your problem as it should be very high. If it remains low (shorted) your problem is not the tube. You HAVE to get the resistance on that cap to ground very high. It is either the tube which you can check by just pulling it and measuring resistance from that cap to ground, or a short near near the tube socket or from the filter cap to the plug for the speaker. That cap goes to the speaker plug to add the field coil to the filtering network and then returns to the second cap. If the speaker is unplugged it indicates the problem is very localized between the cathode of the rectifier to the 12mfd cap on to that plug going to the speaker.
Make sense? Look at the schematic that shows the field coil for the speaker following that first cap. What it does not show or indicated is that is part of the speaker. Hence, going through the wiring to the speaker, through that coil and returning to go to the second filter cap.
Looking forward to hearing your resistance reading with the tube out. Make certain your meter is set properly at perhaps 10K full scale with positive to the cap and negative to ground.
Jerry