After some searching, I decided to just go back to the drawing board and tried to OTA to Gingerbread again. That didn't work, so I tried the RUUs on pvillecomp.com - still no dice. Trying to flash a stock ROM from the same site (and doing steps 34-38 from the aforementioned thread) also fails.
So now I'm completely stuck and just want to return to stock GB. Any ideas?
IncredibleC XD Ship S-ON
EDIT: It turns out that this thread has a link to a different version of the unrEVOked forever patch. I reflashed the CWM recovery, then flashed the patch and it worked fine. So I now have S-OFF - and CM7 installed.