Our likely best hope of a professionally done restoration for a 4K theatrical version of the Original Trilogy probably lies here - with poita’s superb The Original Trilogy restored from 35mm prints ongoing project.
Solely as a member here, I’d recommend anyone & everyone to have a look through the above thread, to contribute to help bring about something that many of us here, if not near-on all of us on this site, want to see come to fruition.
(just a random thought, there…)