I recently found an excellent article on the site The Secret History of Star Wars (which is now defunct but available on archive.org). It that talks about the deleted scene featuring Jabba the Hutt in A New Hope. (For those of you unfamiliar with this, there was originally a scene in A New Hope where Han Solo talks to Jabba at Mos Eisley Spaceport. It was actually shot using the actor Declan Mulholland as a human Jabba, but cut from the original release of the movie. Lucas has said that he had always wanted to replace Mulholland with a stop-motion alien creature, and when then proved too expensive and difficult, he cut the scene. He later put it back in for the “Special Edition” of movie, using a CGI Jabba superimposed over Mulholland. Here is a video comparing the different versions.)
The article goes into a great deal of detail, but comes to the same basic conclusion that I did in my entry about my Declan Mulholland autograph: the idea that Lucas had always intended for Mulholland to be replaced with a stop-motion alien doesn’t seem credible. Mulholland was proper actor, not just a stand-in. He was in full costume, which seems excessive for something that was never intended to be seen. And the scene was not shot in a way that would make the insertion of a stop-motion alien practical (Han and Jabba are close to one another and overlap with each other, etc.) Indeed, the talented people at Industrial Light & Magic had a lot of difficulty inserting a CGI Jabba into the scene even 20 years later. But beyond that, there were apparently no references to work done or even planned for this scene by the people in charge of the special effects.
It seems likely that Lucas had originally planned for Jabba to be an obese human gangster, but he decided to cut the scene due to technical problems during shooting, a somewhat disappointing performance by Mulholland (who isn’t really very intimidating as Jabba), and the fact that the scene wasn’t really necessary to advance the story. Later on, he probably considered the possibility of using a stop motion creature on top of Mulholland to salvage the scene, but quickly abandoned it as impractical given the technology available and his budget. But I have a lot of trouble believing that he had planned that from the begining.
In any case, I for one am very glad that they decided to delete the scene from the original release, as that paved the way for the unforgettable alien we met in Return of the Jedi.