As a content contributor to their work, I just received my numbered Vol 1 to go with the previous Vol 3. This is an excellent book, albeit expensive, and highly recommended for serious K98kcollectors. Vol 1 has extensive coverage of the "Banner" mausers in it.
Karabiner 98k Volume 1: A collectors guide to the development and production of the German K98k service rifle up to 1938
When used in conjunction with BBoW, it gives the K98k collector some terrific research capability.
Regards,
Doug