I was posting this last night when my computer crashed but I once had a ton of my alternate scorings on youtube but they started pulling star wars videos when the blu rays were released and so I had to pull about 20 videos (ugh)
I guess my thouight was, I'm very familiar with all the prequel scores and their sonic limitations, plus also the melodic and thematic material.
my thought was even a rough outline of the scenes and ideas would help create an idea of what is needed where, and based on that, I could compile what we have and find what we'd need. Most of my work could simply be stitching together cues which I'm rather proficient at (I'd hate to say it but the Ultimate Edition of Episode I was an amazing editing job albeit a horrible product).
That way I could kinda... create an idea of what we have and what we'd need...a rough idea at least... The new scenes might need to be fully scored too which would be kinda exciting for me lol but anyway
If it helps at all, I did my own score/theme for the final Harry Potter novel based on what I heard in my head... so it's not entirely an unknown idea to me.