This was posted over in the Theatrical vs SE forum, but I know not a lot of us here look there. Definitely something worth checking out.

Originally posted by: morgands1
This contemporary recording may be of interest to those who’ve studied the differences in the 70mm stereo sound mix vs. other mixes and video releases of STAR WARS.

http://members.aol.com/morgands1/closeup/text/SWaudio.htm
“The Sounds of a Galaxy Far, Far Away”

David Morgan
“Wide Angle/Closeup: Conversations With Filmmakers”
http://members.aol.com/morgands1/closeup</div>