battlebeast
Senior HTF Member
Lucas has said he keeps EVERYTHING, never throws anything away. So no chance he junked the trims.This is not new work drawn over old work. It's an entirely new render and composite with a completely new version of Jabba.
In 1997 the negatives were reconfirmed with new shots featuring the revised effects. However, the original version of Star Wars was completely restored on film prior to any of the SE shots being created. That was the original intention of the project because the SW negative was in very poor shape. Those restored original negatives (or dupes) were used as the plates for the CG effects over the various iterations since 1997. There is no reason to think Lucas would actually trash those original shots, if only to preserve them for future alterations.