I agree that the most widely produced US fighter of WW2, the P-40 series, is under represented in the planeset. The K or N variants would fill that gap rather nicely, and may actually stand a chance against other mid- to late-war rides. Personally, I think the K would be the better choice, and more popular in the MA. For a perked P-51 (maybe 10 points like the C-Hog), how about the Mustang 1A with 4-20mm Hispanos? The Spit9 LF would be a good choice also.