Yes, I think there has to be a lot of truth in that. i'd also agree that the period 1858 to 1863 is worth a book in itself.
Incidentally, high time we had a new book on pre 1860 copper, including the top quality pics that are easily available today. Can't quite understand why we've had several on post 1860 bronze, but none the other way. Maybe it's a period which never quite captured the numismatic imagination.