I finally was able to pull the monitor out of my cab, haul the cab upstairs, and set it up in my room... and there was much rejoicing. That is, until I put everything back together and fired up my GI Joe game. I should have known that I couldn't have moved the thing without a casualty of war (besides more dents and dings)

The picture was insanely bright. I grabbed the board with the controls for the monitor, and I believe I found the culprit... a broken contrast knob. It looks broken, and when I turn the knob, nothing happens. I'm assuming that this is causing my problem. Adjusting the black level helped, but it still isn't perfect.
Is this a safe assumption?
If so... where can I get a replacement part? I tried calling all of the TV repair shops in my area, they were all worthless.
Here's the info from the back of my monitor:
Wells Gardner
No: 25K7131
120V 60Hz 100W Max
It also appears to have a Zenith tube or screen or something.
The location of the broken part on the board says:
VR101
Contrast
The part itself says "10 K (and then some symbol that looks like a script lowercase s) L " on the knob.
One final question... There is a piece of cardboard on the back of the CRT That has a torn corner. (I'm still trying to figure out how this happened, as the back of the monitor never took a hit during transport.) I'd like to replace this, since some of the contacts on the board are showing, and I'd like to prevent accidentally zapping myself. Is this just cardboard, or is it some special material?
Thanks!
Bill