The markings are almost certainly for the American Volunteer Group, AKA the Flying Tigers. They weren't part of the US Army Air Forces until later in the war. They were part of the Chinese Air Force.
http://www.flyingtigersavg.com/
Before you build any model it's always a good idea to do some research.
http://www.google.com./search?q=avg+...w=1440&bih=699