I've figured out how to get this game working in widescreen! You were very close Ross! After changing the screen height/width in the registry there is an additional step. In the debug section change "SkipMenu" to 1. The game will automatically start a new game in widescreen, so to load previous saves you'll have to make use of quick save (F6) and quick load (F9). You have to skip the main menu because as soon as it appears in a widescreen resolution, the game will go back to non-widescreen when you try to load, resume or start a new game.