This is fascinating! The images are way beyond what I expected when I read the first post-- seeing them makes me think "this has to be done!"
So question: What can you tell us about the bookends? Aside from obviously creating the best prequel story you can, the bookends seem key. They need a little magic of their own.
Mentioning the "intermission" makes me think of Lawrence of Arabia. I always loved the bookends of that film-- especially the opening title sequence. Maybe some inspiration there? It would be great if the bookends could seem like new scenes.