I ended going back to 512x384 for now. I was able to compare my junk board to the good one to make sure I got all the modifications reversed, ended up needing to remove one resistor the previous owner had added and reconnect two spots that had been isolated. I might do 640x480 some other time, but for now I don't want to worry about putting extra stress on the board until I can really take my time and replace all the caps. Good news is the display is rock solid and amazingly clear!