I agree with you about the trace of star-and-bar insignia on the door. The RAF returned some of their Dakotas to the USAAF after the war, that plane could be one of them.If you look very closely between the hinges for the rear door, you can see a similar horizontal discolouration which maybe indicates it was the circle and bar of the American national insignia. It shows up more if you take the photo and alter the contrast.






