Luke throwing and missing is a detail that was never on film. Never. Any memory of it would be based on mis-remembering and having an image from the novelization (where that did happen). I have always had a very clear image of that myself, but in researching it, I have found that while there was an early release that features some differences, none have any substantial content differences. I can trace the current (as in GOUT) edit back to 1977. It was for the wide release during the summer of 1977 and matches the international release made about the same time (this was the release the mono soundtrack was made for). The original cut is preserved in Puggo Grand and Moth3r’s bootleg (identified by the original crawl and a mono mixdown of the stereo soundtrack). Both show 3 effects shots and the end credit replaced (the star destroyer shotting at the Falcon as it flees Tatooine; Han, Luke, Leia and the droids arriving on Yavin 4 with the matte painting of the temple; the rebel fighters blasting off from Yavin 4; and the end credits are spaced very differently and a glitch at the beginning was removed).
From my research, the Biggs scenes (except maybe the one on Yavin 4) were cut almost as soon as they were shot. They where the first scenes shot in Tunesia and none of the other scenes were ready so we really have them because Lucas was keeping the crew busy. He was persuaded to write those scenes by friends and after shooting them decided not to include them and stick with his original idea of following the droids and meeting Luke when they encountered him. A lot of the shots were originally longer and contained more dialog or there were alternate shots done and then the dialog revised. A lot of little things got cut. We have at least 3 of them. More dialog right before Tarkin enters the briefing room (including the first use of the word Sith), an extra line from Luke at the end of the scene in Ben’s hut, Liea’s extra line after they destroy Alderaan. Who knows how much more there is. From the description of the B&W rough cut, most of these would have been in it. That cut was done with a B&W copy negative not the real negative. The next cut was done by George and Marsha and the final cut comes from what they did. What they rearranged and decided during the editing process is not something that we have access to. Uncovering the hints that remain in the audio vs. video of the final GOUT cut are interesting.
Deleted Magic made it clear that the scene in Ben’s hut was redone because the lightsaber section and the Leia’s message were flopped (watch C-3PO - he is off at the wrong time and on at the wrong time). Luke missing during the trench run could have also been in there (the Deleted Magic team certainly thought so). So what the film looked like before they made the final changes is certainly not what it looks like now. Even the SE retains all those editing choices, even if it replaced some of the shots with new ones or longer ones. The biggest changes to the film outside of those are a slightly different framing choice of the scenes that bracket Jabba’s scene (like all the fades and wipes, they were FX shots and they went back to the original negative to redo them for the 97 SE and they changed the in and out points).