I went to a paper at SMPTE several years ago about converting Star Wars to 5.1 sound.
It turns out no one thought to store the main master print of the movie in an-archival manner. It was on some shelf in a building with no humidity or temperature control. The studio was annoyed they had to spend $10,000 to clean the print before they made 1 billion dollars on distributions for the DVD and re-releasing for theater.
Don't under estimate the stupidity of the movie industry.
They could have built a single vault just for that movie. Anyone who saw the original run of the movie would have realized this is a big deal, preserve it. But not the Star wars gang .