I thought that Gold simply added the Return to Na Pali expansion, but according to wikipedia: "Additionally, the games were updated to run on the Unreal Tournament version of the game engine"

Does it mean Gold uses a different updated version from the original? How different is it? Is it possible to switch to the original engine?

Thank you.

Would you by any chance know of screenshots that show the interface differences (sorry but googling helps very little since it brings up mostly results of more recent games)?

EDIT:
I found screenshots on mobygames.

So in essence, the original Unreal interface looks like this:
http://www.mobygames.com/game/windows/unreal/screenshots/gameShotId,1509/

But Gold uses the one like this (from Unreal Tournament):
http://www.mobygames.com/game/windows/unreal-tournament/screenshots/gameShotId,2980/

Would that be correct?

Thank you very much.