I think you need 065 version 1.1 of the enabler to use with 7.1 and if you don't want to hack your monitor to support 640 x 480
I also have a CC and have been keeping an eye out for a LC575. You can find a link to the v1.1 enabler on my site
This should be easy. I seem to remember from looking at the pinout the last time that there are Vid pins present on the ZIF module which tell the VRM on the logicboard or carrier card what voltage to deliver.
The buck controller on those however has digital input pins (usually 5) to set the voltage. If you have a G3 board it should not be hard to trace the connections from the controller on the VRM to the ZIF socket and from there to the correct resistors.
Did not yet look into the Nubus upgrade any further. But will do once interest in that one kicks in again