Just to give you a heads up:
I just uploaded a GOUT-sync’d version of this recording into the website of the human organ.
To address the missing 6 seconds of audio from the Wampa sequence…
…the audio of the Wampa cave fight - prior to Luke using the force to retrieve his light saber - is about five-and-three-quarters seconds shorter in 70mm than the 1985 and 1993 transfers,
Here is an MP3 comparison of the Wampa scene.
It begins with the scene from the 70mm in-theatre recording, followed by the 1985 BetaHifi tape. Then I put the two in sync - 70mm in right channel, 85 tape in left - which results in a nearly six-second gap.
…I just put silence over it.
I do realize that there has been speculation over the missing audio of the said sequence. Perhaps the cause of the speculation was the fact that the edit didn’t come with an anomaly, like a “pop” sound, as you would hear it on an optical track from a 35mm print. But, because this audio is from magnetic tracks of a 70mm print, and since no one from this thread…
… can recall any footage missing from this sequence, I’m going to go with TServo2049’s theory
If some accident occurred and that section got boogered up, the projectionist might have had to cut it out just so they could continue running the print. 70mm was expensive, so it was probably a lot harder to get a replacement print, especially on short notice.
In other words: the film broke during a previous screening of this print and the projectionist was able to rejoin the broken ends together, even the magnetic tracks, so, that the audience didn’t hear the “pop” in the film splice.
As for the alternate edit of the Rebel Fleet sequence where these 3 GOUT SFX shots …
…didn’t exist at the time of the screening, I left those shots silent, too.
So, for the moment, this recording is the closet we’ll ever get to the first-released cut of ESB.
My thanks go to OT member morgands1 for capturing the audio and for making it available to us.
EDIT: I had a link of a video I’ve made of the said alternate ending with the In-Theater recording unedited, but I 've later found out that there are several videos of this scene out there on YouTube.