[Jamie]

Your question about what was powering the tubes, it made me look further. Remember when I said that nothing is connecting resistor #55 to the cap? .. Well, one of those three wires I mentioned (from resistor #55), it runs to the RF, but then another wire was connected from that point to the other #67 cap (call it wire #2). Basically the problem was, everything was hooked up to one single 8mfd cap. That's where the hum was coming from! I removed the wire I installed, and moved the wire #2 to the other #67 cap. All is fine.

This radio had been worked on before I got it. The Electrolytic Caps were replaced sometime back in 1945 (from the looks of it). I just replaced parts, so I don't know if I made the wiring mistake or if I just copied it. I recapped this radio back in the summer. It was one of the first radios I ever repaired, so it could have been my fault. I put it aside because it hummed. It has not been used since.

Anyways, the problem is fixed, and a huge thanks to everyone who helped me, especially Morzh!. I learned more everyday.