I took a look at some of the photos of 353rd aircraft, they had Mustangs and T-Bolts. I know that the Mustang is a real fun one to get the checkerboards on the nose m8.
Your best bet would be to look at another skin (I think some of the default ones have checkerboards) and see how that person dealt with the distortions. Also of note, the a/c in real life were not perfectly painted as you can see in this photo. (It is from the Little Friends website which is an excellent source for info and photos.) It looks like they had a bit of trouble getting good square checks as well!
8th Air Force Fighter Group - Littlefriends.co.uk
Hope this helps you a little m8, if you still have troubles, a few more details of what exactly is giving you trouble will help.
