They have claimed a stop motion creature would replace the actor in 1977, but Phil Tippet didn’t get instruction on designing Jabba as a ‘Sidney Greenstreet’ type character until later…
Yeah , and there’s something suspect about the whole narrative . In the 1983 Documentary , From Star Wars to Jedi The Making A Saga , they go over it and show a part of the scene as originally shot with Decan Mullholland and then show a storyboard of what the intended creature effect of Jabba was supposedly going to look like , superimposed over the human figure on the storyboard . Giving the impression that it was an archival piece of artwork from the time of the shooting of the original film , except if you look closely , you can see what appears to be Salacious Crumb on the ground next to Jabba ! The little guy was never talked about , seen ,or mentioned until 1983.