BTW, I also came across this Online Book: Historische Rang- und Stammliste des deutschen Heeres, Klaus von Bredow, Ernst von Wedel, Berlin: Scherl 1905. This book has a complete history of the German army, its staff and its units from before 1654 up to 1905. Also on-line at Preussischer Militargeschichte, where information is constantly added to complete the history up to
1914.
http://www.grosser-generalstab.de/index.html