That is strange. A TH400 code is 2Z for NOR (2M for LOS). I would think there should be some transmission code (2M,L,Z,or B) to follow when a 4N code exists. You can try comparing the VIN to see if it falls within the 03D period that's stamped on the tag. Also, compared the VIN tag on the door jamb with the hidden VIN that may be visible looking through the cowl grill to make sure they are the same. Is there a factory clock in this car? Can you get a closer view of the tag so the 2R (?) is more clear?
Mike