Glad you enjoyed it Harmy!
So a couple years ago, I watched all the versions of THX side to side so I have a pretty good idea at what the differences are and where to find them. Also, as the creator of the Grindhouse version, I can safely say that while it wouldn’t be impossible to despecialize the film using the Bluray, anyone attempting this is going to run into the following issues:
The computer screens: all of the warning signs are in Italian on the print and therefore the only other sources we have are faded and cropped 16mm prints and the LD. These were all changed for the BD.
The scene with THX and SRT in the room with the fetuses: this occurs at a reel change and there is a good chunk of footage missing on the print at this point in time. To make matters worse, the bottles were ‘enhanced’ on the BD, so this would require some kind of rotoscoping using the LD or the 16mm prints.
The sunset ending: It’s a shame that the end titles are in Italian on the print because the BD sunset has some weird halo-ing artifacts around THX (noise reduction artifacts?). Maybe this can be fixed…?
TL;DR: It’s a shame we don’t have any more sources to work from like we do for Star Wars.
Perhaps another print will show up one day?