Thank you Taz for your comment

Unfortunately I can not see the second plate on the one of the first three prototypes and not on this particular plane flown by Voss. All I see is that on the fuselage behind this plate is paint damaged by leaks. Glad that you like detail about the extended yellow on fuselage panel. Maybe the whole top metal is yellow but this can not be proven. This area is under the shadow and also there is maintenance area. Many dirt from machine guns grease, hand prints, dust... oil, gun smoke traces maybe over... impossible to determinate option for yellow. So let it as it is. About the datum line on starboard side... I did not note in the moment..
New color profile is the Fokker Dr.I fighter flown by
Rudolf Stark. I am not sure but on the side of fuselage, behind the engine cowling have to be placed rounded access panel.