Welcome to the board, and thanks for your reply.
Entertaining but frustrating & on balance, I'd advise you not to bother with it.
This is kind of the reply I was expecting to hear...
The only other English language book about this scene that I'm aware of is the Sonore encyclopaedia, which is very dry & not really a book to be read, just dipped into, so I did have (perhaps foolishly) high hopes for this. But that book does have more actual facts in their one page on Rallizes than Cope has in his entire chapter.
I wrote that Rallizes piece in the Sonore book, back then there was very little to go on; nothing at all in English, other than something I think Alan C had run in the Wire magazine. Obviously in the 7 or so years since the Sonore book came out, a bit more information has surfaced, but I doubt there'd really be enough to fill a book chapter without resorting to a lot of conjecture and myth-building. I guess Cope had people to help him with translations of the various Japanese articles out there on the Rallizes, etc.