I started doing something similar a couple weeks back -- trying to recreate the SICP LaTeX files so that I could generate my own beautiful PDFs, instead of using the slightly wonky HTML edition.
I even sent an email to Hal Abelson asking after the original TeX files, figuring it was a shot in the dark. I was blown away when he sent me a response... in less than an hour! He told me that he didn't think they even had a copy of it anymore, and that he didn't think it would be very useful in any case, but it was still really cool to get an email from a programming legend who has touched so many lives.
Too bad I forgot to ask for an autograph! ;)