@ helios: I suppose that's true. There will undoubtedly be some optimizations and changes made by the tool chain that the original authors never wrote. Degradation of the code is unavoidable when you RE something like this.
Good stuff. Reminds me of a guy named cvet that recreated Fallout 2's mechanics using a custom engine built from scratch ("FOnline"), but got past the legal problems by requiring you to still have the game files yourself if you wanted all the graphics/critter data.