These threads may be of some help - from just a quick ‘copy & paste’ from the An Index & Help Thread for Preservation of Other Properties…:-

In the projects section…

THX 1138: The Original Version - by Rikter
THX 1138 “preservations” - by msycamore
THX 1138 Japanese letterboxed LD preservation - by csd79
THX-1138 (1st Director’s Cut) 35mm Grindhouse Edition - by Mavimao
THX 1138 1971 ‘Flat’ Theatrical version preservation - by poita

In the Discussion / unfinished projects section section…

THX on 35mm Tech IB preservation - HELP NEEDED - by Chewielewis
THX 1138 “preservations” - by thxita
THX Italian 35mm - Feedback thread - by mysycamore
THX-1138 Original Warner Brothers Cut (1971) DVD-5 - by Trooperman
HD Transfer - THX-1138 (720p) - by nookupeous
THX 1138 1971 ‘Flat’ Theatrical version preservation. - by poita

THX 1138 - What a Special Edition SHOULD Be. - by ReleaseTheOriginals (in ‘Theatrical Cuts vs. Subsequent Releases’)
THX-1138 - by Trooperman (2005 discussion in ‘Media: Film, TV, Books, Comics, Games, and More’)
THX-1138 - by Luke Skywalker (2004 discussion in ‘Media: Film, TV, Books, Comics, Games, and More’)

a site search, (click here if you don’t know how to do a site search), may yield you some more results - good luck with it 😃

The above link will take you to the ‘How do I do this?’ on the OriginalTrilogy.com thread, in the ‘General Assistance’ section.