Thanks chaps !
As I found out there was two types of step plate for pilot on the D III Oeffag's, one type with the perforated plate as a small door to close the " hole " ( it was a simple mechanism, the plate-door had only a hinge with a spring and it opens when the foot is putted in and closes after ) and the other type was without this " door " just the hole was left on the fuselage. I decided to make the first one. I used aluminium kitchen foil for this task. First step was to find the " master " for the perforation, the guarding mesh for rear window for GMC CCKW 353 Truck in 1/35 scale fitted perfectly. I punched out a 2.5 mm circle from the foil and just simply push it on the mesh so it took the shape of the mesh, then I split it on half and put it on it place on the fuselage. This is how it looks :
Albatros DIII Oeffag
Albatros DIII Oeffag
Albatros DIII Oeffag
Albatros DIII Oeffag
Albatros DIII Oeffag