Aren't British film sets always burning down? Though Wiki tells me this:
http://en.wikipedia.org/wiki/Millennium_Falcon
"No new models or sets were created for Return of the Jedi. A portion of the full-scale ship was used for a scene cut from Return of the Jedi "
possibly because the original fullish scale model:
"weighed over 25 tons and used compressed air hover pads for movement around the set."