I think it works great as is, but I would think a 40 would look great to(but I do like my jackets to fit rather trim so just my two cents )New around here, but been lurking for a while. Looking to tap into the wisdom of the lounge crowd. Picked up this p613s size L from the classifieds this week. Need some objective feedback on fit. The chest, arms and shoulders feel right but the body seems pretty voluminous on me. I'm a 42 in Vanson with a 41 chest and 31/32 waist. This jacket is really nice, comfortable and badass...so I don't trust myself.