Friend of mine had this photo in an album from her grandpa. Thought I'd share it. Don't know much about it though.... any input would be interesting I'm sure. Looks like a "C".
The Squadron, now designated the 40th Fighter Squadron of the 35th Fighter Group under 5th Air Force, was ordered on 2 June 1942 to Papua and began flying missions over New Guinea. This may be it...based out of MI at least.
http://www.40thsquadron.org/organize.html