Not sure anyone has caught it but:
http://forums.civfanatics.com/showthread.php?t=511396
the process can also be used to convert civ5 stuff to civ4 (if the polycount doesn't hurt the game)
Good to know! Beyond my capabilities on the Mac I think, but if someone wants to convert the Polynesian Hokulea and Assyrian Siege Ram to Civ4 I (and I imagine many others) would be eternally grateful.