I actually have been spending all of my glorious free-time at work today working on it. I am about 3/5ths done with the structure. The battle over the Sarlaac is the thing that is giving me the most trouble now.
The novelization by James Kahn is immensely helpful. It seems to indicate that:
1. The book was written off of the shooting script based on how nicely (and unexpectedly) it dove-tails with the scene break-down in the Making of the Return of the Jedi book.
2. The dialogue in the movie was nearly always a match to the novel, and by extension, the shooting script.
I have also come under the impression that the scripts on the net labeled 'revised second draft' and 'third draft' are simply re-worked versions of the published, public draft (published in the Art of the Return of the Jedi and in the Annotated Screenplays. These re-worked drafts (especially the forged two different revised second drafts) take scenes that had been published in outside sources, such as the sandstorm sequence, and dropped them in where they belonged originally.
The fake scripts also have re-incorperated into them many of the Urban Legends of Star Wars, such as the false idea that the Lando and the Falcon didn't escape the Death Star in time. Another version that some fan likely put together has Han dying as well, being wounded instead of Leia at the bunker.
So, I am fairly confident I can piece together a reasonable facsimilie of this lost script. I ought to be at least able to get the scenes in the right order. I would just like to make sure the dialogue is as correct as it can be. This is where I could use help finding story boards and call sheets. For instance, these call sheets have been very helpful:
http://swnz.dr-maul.com/moretext.php?request=bio_GHome_03
Feel free to chime in with your 2¢. Boo Yah!