Does the book go into any depth about those issues (even today they’re largely classified, so I suspect not a great deal of detail).

Well, this is the author:
https://en.wikipedia.org/wiki/Andrew_Brookes

Apparently this ex-RAF Vulcan -and Victor pilot used to be a NATO Nuclear Release Officer. Whether he will divulge many hitherto unknown details in a “Haynes Manual” I do not know.
This book will not be a thick “Tome”.