One such I think is the extended "Rebel Fleet and Finale." It fits over the sequence, they just choose NOT to use it. (Make sure you use the correct, extended edition one).
What might also be interesting is having an alternate score track to the film... so much of the score isn't used or is only partially used or alternates are used... that it would be cool to see the film as it was intended.
One thing I want to recommend off the bat... the tracked fanfare of Han riding his taun taun into Echo base after Luke is attacked should be replaced with something else.
Not neccesarily the original music... as I can see why it's not used... but something else.
I also think that the opening to "Imperial Walkers" should be Re-inserted... and perhaps even replace the tracked music for the opening of "Snowspeeders take flight" with the original music.
If you want to see what some of the scenes look like with the original music, check out my vids:
Probe Droid Alt
Wampa Ice Lair -etc
Probe Droid
Yoda
EDIT: It might also be worth moving around some sequences... like... between Han and Leia arguing about Chewie needing a good kiss to then 3PO and R2 talking about flooding the princess's chambers... you could insert some of Luke into there I think... just an idea. I tried keeping up with this thread but it got away from me so I apologize if I'm too late or beating a dead horse.
I also volunteer to rebuild any sfx/music mixes you want. I have tons of Star Wars sfx... and I'm the music guru lol can even output in 5.1 for you :-p