Around -1248, 13328
Around -5632, 648
I'm using the latest svn and...yeah I don't know.
I aligned all these textures as you can see here BUT in the GZDoom 3D mode they appear completely different, and thus in the game they are aligned completely differently. I can't align anything in the GZDoom 3D mode so there's really nothing I can do about it. The metal walls around the area were also fixed but don't appear that way in-game.
I also couldn't get the wooden bridge flat on the red castle area to rotate the right way. It probably needs to be done through a script or something but I'm no good with that. Changing the rotation property didn't do me any good though.