I have a set of the decals produced by "Wind in the Wires" (a one-man shop) for Jasta 40s. *His bibliography shows nine separate references. *The research is extremely well done, and where there are unknowns he states these. *I just wanted to preference where I picked up my info on Degelow's D.VII.
Degelow's D.VII definitely had the Jasta 40s markings of a black fuselage with white tail. *As is known, his personal marking was the white stag. *However, regardless of what Roden thinks, according to the "WinW" documentation, this aircraft had
five-color lozenge, applied chordwise. *Roden was correct, though, in the angled white bar on the top wing, running from front port to back starboard. *In addition, the rudder/fin cross was asymmetrical, again, as Roden has depicted.
It looks like the only thing Roden was mistaken on was the lozenge.
HTH, YMMV, IMHO...