Well, I don't have very much in the way of civil aviation in the wings. The closest I can come to civilian a/c from that time frame is a 1/144 Minicraft C-118. Now, the kit I have I bought from a lot of built-up stuff. I was gonna strip it anyway. I have posed the question of 1/144 decals in the forum before but there are not (were not?) too many AM manufactures of 1/144 decals. I wouldn't mind putting it in American or United Airlines livery from when the DC-6 was introduced in '46. I don't have the kit in front of me but the "windows" were just decals anyway and the cargo door could be filled and sanded.
Actually, Minicraft has a Lockheed Electra in their line-up that comes with early American Airlines markings. I found a pic on the Web of a DC-6 and the marking are pretty much the same. Hmmm...