I have discussed the engine access hatch issue with Wingnut Wings and Richard Alexander commented that the placement of the hatch varies between the 160hp engined Albatros and the 180hp engined Albatros
"The kit's draincock cover/hatch was modelled in the correct position for the majority of the kit decal schemes, which are 160hp Daimler-Mercedes D.III powered Albatros D.V.
The draincock on the 180hp D.IIIa engine, which powered almost all Albatros D.Va, is further forward."
. . . which just goes to show how much research WNW do. When the deluxe version of the kit comes out I expect there will be PE hatch covers which can be attached in either position.