long time no see, but I think I've found something special for you. This Airacobra is pictured in Freundts/Büttners "Rote Plätze", page 36 (great book, anyway), during an engine change on an airfield in Germay. It is finished in a light grey color overall, maybe AMT-11 or -7. I believe that this color is not just faded olive drab because the coloration is very consistent and the original serial is missing, i.e. overpainted. Also note that the fuselage and upper wing color is most likely the same as the color of the gear cover, so this Airacobra might be finished in one single grey indeed. Also compare "White 44"s appearance with the other aircraft visible on the pic.
What do you think?