Puggo - Jar Jar's Yoda said:
In June I saw 35mm/mono three times in a relatively small theater in Utah. My memory was the movie being fantastic and the image being marvelous.
In July I saw 70mm in a large theater in California. My memory was that the image was better, but that could have been excitement, or just a better projector.
Late in the year I saw it again - I'm not sure the format, and I don't remember any particular thought of whether it was better or worse. I believe it was probably 35mm and stereo mix.
In 1985 I saw a marathon of all three films in a small late night theater. The image quality was atrocious and I was sad to see the film(s) in such a damaged state.
I do have two memories that don't jive with historical record - like being quite certain that in Utah I saw the Biggs hangar scene all three times, and NOT seeing Vader survive and fly off. Before everyone assumes I'm crazy, I would also like to point out that I also remembered "close the blast doors" despite wondering where it went in every subsequent viewing. It wasn't until joining this group that I learned that my memory was actually correct in that case, despite the lack of any intervening confirmation. Regarding the Biggs scene, upon seeing it in the SE, my mind was able to fill-in the removed chunk of dialog from memory. And no, I didn't see it in the documentary because I only saw that for the first time very recently. That's my story and I'm sticking to it!!! :)
Is it possible you saw one of the many SE clips or documentaries around that time? the Biggs hangar scene is present in both the '77 MoSW-documentary but it also appeared frequently in '97 SE promo material. That these differences were in some early cut of the film would be crazy but being that this or these mono mix prints of Utah featured an early cut of the film sounds really crazy. When prints with the Academy mono mix finally arrived the film had run for almost a month, it's one thing if Vader wasn't shown regaining control of his ship, Biggs talking to Luke in the Hangar in some of the early Dolby Stereo prints.
As the anal retentive guy I am I have discovered a very subtle visual difference in the '77 film besides the two variations on the end credits roll, see here: http://originaltrilogy.com/forum/topic.cfm/Print-variations-in-77-Star-Wars/topic/14705/
We now know that at one point a revision of the end credits roll and the Yavin X-wing & Y-wing takeoff took place, the latter being located on the last reel as well. Being so minor, these two revisions are actually in some ways more crazy to me than taking out/adding the Biggs hangar scene and taking out/adding a glimpse of Vader at the end, both of these would conveniently be located on the last reel as well. I cannot change your memories and I don't say you are wrong but I do find it very hard to believe that several of these revisions at different stages took place and especially being screened as late in its run... an early cut with the late mono mix and even some UK prints showing this early cut.