To photo war -Thank you for sharing this nice photo. This circular opening in extension plug is not photo defect, it is circular access hatch as Broncazonk right said in his comment. You can see this hatch on my attachement. source: Fw190D ersatzteil-liste 1944
I think, John Manrho is right with JG6 black 3. When I comparing mottling around vertical bar and camouflage style around balkenkreuze, I think this matched well with known photos of this a/c.
some photos to compare from expired ebay auctions
1.
http://www.modelforum.cz/download/file.php?id=1037984
2.
http://www.modelforum.cz/download/file.php?id=1038150
3.
http://www.modelforum.cz/download/file.php?id=1038152
4.
http://www.modelforum.cz/download/file.php?id=1038148
5.
http://www.modelforum.cz/download/file.php?id=1038149