The current version of the “Original” Star Wars Trilogy available is only the most recent version of the Special Edition. This version has shots that completely replace or obscure paintings, models, or effects that the original artists worked hard on a deadline using technology they were sometimes inventing to complete. While some of the Special Edition shots may look better, the original deserves to be preserved and available outside of fan restorations (which were used in the example images below, compared with the 19SE).
Below is a gallery of shots where the original work is just gone.
One of these is a Special Edition shot, but someone worked hard to animate the Scurriers and the landspeeder that were replaced for the 04SE.
(Yes, the 97SE Jabba deserves preservation)