More about the codex as inspiration idea:
Last Friday, I did something that might be helpful to the project: I took all the previously published pieces* and conference papers I want to put into this book and put them all in one big file. Yes, it's messy, but it was exciting to see about half a book's worth of manuscript all together.
It was even more exciting when I printed out the entire mess. It was truly a stack of paper. Now, we all know that a stack of paper does not a book make, although with some books I've read, I've wondered whether that was the organizing principle behind the whole thing. In reading the pages and marking them up, I started thinking about the ideas in different ways. I also did some cut-and-paste in the big mess o' articles document. That advice about how helpful it is to "touch your work every day" was even more true when I could actually, you know, touch the pages.
Of course, what I've really done is made something that looks like a manuscript but isn't. You know the cargo cults that make airplanes out of packing boxes so that airplanes will come and material goods will follow? The faux manuscript is really just my airplane made of packing crates.
Still, if it helps, count me as a believer.
*Not more than two of these, of course, because I want a publisher to accept the book.