One way to know it it is a T-6 or a Harvard is to check the control column. Pistol grip, it's a t-6. Spade grip, it's a Harvard. The T-6 at the Castle Air Museum in Atwater Ca is a Harvard MK II and the markings would cause it to be considered as T-6J since there were some taken into the U.S. inventory post war and sent out under the MDAP program.