Ok, I found a schematic here:
http://www.nostalgiaair.org/Resources/295/M0013295.htm
It looks like this set has a rectifier with a cathode, that runs off the same heater winding as the rest of the tubes. There is b+ on the cathode, and the heater has one side grounded. A setup like this is a short looking for a place to happen. I'll bet it's the rectifier tube (84).
At some point fuse the power transformer. It could happen again.
All the best,
John
Edit: The electrolytics could be shorted, also. Now would be a good time to change them if you havent. 17,18,and 43 on the schematics being likely suspects.
Any paper caps that are still there will likely cause grief, too, sooner or later. Probably sooner. I'd change them out. In some old Philcos they are in bakelite blocks.