Prepar3D came with a free copy of the Milviz P-38L, and I noticed that the stars and bars was missing from one of the booms.
Just before I wanted to start laughing I realised that it was one of my own paints...oops!
I did not even know one of my paints comes standard with P3D, but I feel mighty proud about that, apart from that missing roundel of course, so I made an update:
now with roundel! Go here to download if you want your default P-38 to be complete.