You will be pleased (or maybe not) to know that I have started on the new book; I should have been doing it since October, but in the end the final stages of Laughter and a new Part II course meant that nothing much got started till January 1.
This one is a rather hubristic enterprise, as it is a history of ancient Rome from "Romulus" to the third century CE/AD (working title is SPQR). I never imagined that I would ever take on such as project. But if you can't do it when you're 59, when can you? (Earlier one wouldnt know enough, later one might be on the downward spiral.)
Anyway, I am now on the part of the process that is (more or less) unadulerated fun.