You redid it already? Darn, I just grabbed the frames from Puggo Grande and was going to post them up to show which frames were smeared, which were repositioned, etc. :)

I still will, though. http://imageshack.us/g/109/shake001.png/

Go through them in order, and you'll see that some of them were optically smeared and repositioned, while others weren't. There was no blending of one frame with another - each frame is a manipulation of a single frame of the original footage.

No idea why they didn't try to recreate the effect in the SE; judging by the almost perfectly recreated optical wipes, I bet that a similar recreation of the shake could have been done.

Also, I don't think Ben Burtt's anecdote is referring to the burn marks. He said there was a jumpy spot when the Stormtroopers burst through the door. I think I can almost see a jump when the door explodes, but I can't tell if that's what Burtt was talking about, or if it was an intentional jump cut, or if it was just my imagination. (Maybe Mike Verta knows what the "jumpy spot" is Burtt's talking about?)

As for the burn marks, I wonder if they are connected to the optical "camera shake" effect. While going through the scene frame by frame, I notice that the artificial shaking ends right around the time the burns show up. I don't think they were introduced when the effect was done, because the 80s video transfers don't have them, and it doesn't look like the effect was recreated.

And the fact that the '77 shake was an optical effect may be why the scene was replaced in the SE. Since it was an optical, perhaps it was one of the scenes that was on CRI and was so deteriorated as to be unusable?