After much thinking, doing, sweating and swearing the book machine is ready.
I took a chance in not assembling it fully to test that I'd got it right, and I got away with it. Just a few small clashes of screws and skirting boards - nothing a pair of pliers and a Leatherman couldn't handle.
The corner is in FirehorseMia's new/old place, the design to maximize shelvage in the available space.
The purpose of the wedge shapes on the top two shelves is difficult to explain, but should producing a cunning curve effect. Maybe FM will post a pic when it's in operation.