Really need some quick help here. I'm looking at two madras shirts from SS2011 on final sale right now. I haven't bought any shirts from J. Crew in awhile... just shorts and some of their third party stuff. What's the chest measurements on a medium? Tried doing the chat with a specialist thing. She helped a bit, but could only give me a chest circumference of 45" for a medium, which seemed a little big. I'm a medium in Gitman Vintage. Should I go small on these??