From their announcement:
One of the good thing of PDF books is the possibility to update files.
At the time I wrote the Gear Krieg Banzai book there were no suitable American 15mm Zombie miniatures around, that changed when Rebel Minis brought out their WW II US Zombies. Enough reason for me to get 50 of them, let them paint by Modartis Limited as USMC and take some suitable pics to update the Banzai file.
All who has already bought the book should have received their update note by now. You can purchase the book at the Wargames Vault.
All units in this book are consistent with existing units in the Battlefield Evolution: World at War and Pacific War books, also written by Agis Neugebauer!
This book requires the use of Battlefield Evolution: World at War, available from Mongoose Publishing.