@gblair: Turns out there are some other mistakes to be made by following the kit's instructions, mistakes easily spotted if one googles "photos of Miss Port Columbus at 1949 National Air Races" and comes up with the article by our renowned F2G expert, Rodney Williams, over at ARC. The wings are not clipped to where they were in 1949 by his explanation and photos he took at the time (should be clipped to the outer end of the ailerons for the 1949 configuration), or the exact placement of various decals on the aircraft - also obvious in the photos.
A further reminder to do ALL your research BEFORE cutting parts off the sprue. All that information above was literally found within a minute of asking Der Google the right question. I asked it too late because I just wanted to see if there was anything that showed what the exhaust stains looked like post-race - and I got that, which will make it look a bit more interesting. But not as accurate as it could have been. Lesson learned (this time).