Well, in II and III, models were used less for ships and the like and more for blue-screen replacement. Miniature sets were built (like the hallways in Kamino and the Geonosian arena), photographed, and comped in around the actors. Hmm, but were there really any models used for Sith? Nothing comes to mind right off. Any help here?
And ThatArtGuy, thanks for correcting me. Yeah, Home on the Range was the last. I didn't see that one either...