Thanks to some good questions from Mage I spent the last week figuring out how to 'package' the book, and how to end it. Remember those flaps sticking out the back end?
I've started to work from the back. Even with my fancy diagram I'm still making mistakes about the tabbing. Haven't started glueing yet, just cutting, scoring and folding. My brain doesn't want to deal with all of this, but I'm pushing it. Correcting the diagram I found several mistakes confusing things, which I clarified, I hope.
Horizontal yellow bars are the pages of the book, joining both sides. Three larger angles are pictures showing the depth of the tunnel, which pull apart to show horizontal structures, the bridges. Thinner, smaller angles are the water feature along the sides of the tunnel.
The rectangle at the bottom of the diagram becomes the wrapper for the book, reversing direction and fastening in the front around the compressed book, which is about one inch thick. The wrapper worries me, because it will fold in both directions, creating possibly destructive wear on the paper hinges.
I began working on the wrapper assembly and glued an additional strip of card over each of the tabs. This made the whole thing too thick and cumbersome. Back to the computer I printed the two small pieces, bottom right, together, eliminating the need for one set of tabs, and reinforced the fold with linen tapes; did all of the first glueing steps working backwards through piece 9; and put everything under weights to dry flat. I won't continue working on it until I see how everything dries.