About listing the various differences in audio mixes, it was a long time since I last listened to it but the Mono mix really is chock-full of subtle differences to the Dolby Stereo tracks, one difference I remember, is the added soundeffects of static distortion of Leia's hologram in the garage.

You also have the added soundeffects of the X-wings "Lock S-foils in attack position".

And you also have the whining sound of Red Leader's ship (I think that is the pilot) before he crashes to his death "Stay there. I just lost my starboard engine".