If you have a multimeter you can verify that you are pumping in at least 12v, but you did say that you tried with a new Jameco...
When my resistor failed and I opened up my PD, I found my resistor cracked in half (and another poster here also reported the same thing). I wonder if yours may have cracked as well, but still partly works which would explain it getting half as hot.
Those resistors are very cheap as you can see, so you can pick up a few of those.
The biggest job is in removing the wooden plug in the bottom. I used a very tiny screwdriver hammered in along the circumference to break that seal, but there will also be areas still attached by glue that you cannot reach so it can be pretty difficult to remove at first.
If you're going to go as far as to make a new wooden body, I'd suggest doing what you can to insulate the heat from the wood so it doesn't char like the PD did [ie: how the CeramicRockZap did it]. However it will take some experimentation because that can drive up the heat inside the port to combustion levels if the heat isn't able to escape as easily as it did inside the PD.
Good luck!