Looks like you conquered the tripod challenge, Russ!
Excellent superstructure.
I think your assessment of the Prados book is accurate. More about what the Combined Fleet and what the U.S. forces knew about it than how they knew about it, although as I recall, there is a fair amount early in the book about U.S. Navy intelligence officers and their education.
For a really detailed account of U.S. intelligence, focusing on ULTRA and the Southwest Pacific Area, but with a lot of good info on Japanese military intelligence, I recommend Ed Drea's
MacArthur's ULTRA (
MacArthur's ULTRA). Ed is, in my view, the premier American historian of the Imperial Japanese Army alive today (see, for example:
Japan’s Imperial Army and
Edward J. Drea on Japan's Imperial Army). His Japanese is as good as his English, and he has an enormous range of Japanese contacts, including surviving military officers. He is also a friend of some 35 years, ever since we were both on the faculty at Leavenworth in the late 1970s.
I'm eagerly looking forward to more
Swayback Maru construction. It occurs to me (thinking of the Battle of the Komondorskis and the Treaty Navy) it would be neat to see builds of an
Omaha class light cruiser (
Richmond) and
Farragut and
Benson class destroyers. Just sayin' in case you haven't already plotted out your future production schedule.
Don