One other thought, what reviews do the various Eastern European boxings of the Allison-powered Mustang gather? I know there are several different boxings out there, but I have a sneaking suspicion that they all use the same molds.
Too, there is one other alternative that, because of the parts breakdown, is a bit more trouble to work with. The old Lindberg P-51B does have the correct wing planform in that area (just checked). It also has raised panel lines which may be a problem, but it does have the right outlines.