Update from what I've been able to research:
70th Landwehr Brigade: Generalmajor Breithaupt
1/,2/,3/5th Landwehr Regiment
1/,2/,3/18th Landwehr Regiment
1st Ersatz Machinegun Company (from Graudenz)
but is it the same unit???????
Research can be sometimes very frustrating.
On page 144 of History of German Units WWI, the 70th Landwehr Bde was attached to the 6th Cavalry Div (Dismounted)