See, from your cited work:
http://books.google.com/books?id=V2sMAQAAIAAJ&pg=PA822
Note: 'Landwehr 1' and 'Landwehr 2'.
1 L St = 1st Ban Landwehr Stab.
2 L St = 2nd Ban Landwehr Stab.
Just one man's opinion.