I recently acquired what appears to be an extremely rare photograph. It was purchased at an estate sale auction in Europe. The photo was listed simply as "Flieger in seinem Doppeldecker "Bülow" (aviator in his biplane "Bülow"). No other I.D.
The "Flieger" is recognizable as Ace Leutnant Walter von Bülow, but he seems to be sitting in the rear seat, of a 2-seater biplane. This is evidently a photo from very early in his service (FA22? FA300?), before he joined Jasta 18 where he flew an Albatros D.III. This plane is clearly no Albatros D.III.
Based on the triangular bracing over the fuselage, I suspected this could be some AEG or Rumpler design. What's leaving me completely confused, is that the wings have a third pair of struts, just visible at the left edge of the photo. Could this be a single-engine two-seater bomber of some type?
The photo doesn't give much to go on, but I know this aircraft must be from early in the war; probably pre-1917.
Can anyone help me identify this plane?