As part of a personal project dedicated to delving into the script history of The Empire Strikes Back, I put together a loose reconstruction of the original 1977 story treatment by George Lucas. This involved combining information from a number of sources, chiefly JW Rinzler’s book but also supplements (including the whole of the first two pages) from Michael Kaminski’s “Secret History of Star Wars” and (to a lesser extent) “Star Wars: The Annotated Screenplay”. To my knowledge, this is the closest to the original story treatment that a non-insider can get.
You can find it here.
Let me know what you think (or if I’ve made any factual errors).