Your number you're looking for on the radiator support is probably on the drivers side, and will be on the vertical part instead of the top. Look in the gap between the radiator support and radiator, towards the drivers side....if that make sense. If it matches the number you found at the rear of the car, and not the dash VIN and title.....you may end up with a state issued VIN # riveted into the drivers side door frame. You had nothing to do with the swapping (if it was) and the NCDMV Inspector will give you Brownie Points for being honest and wanting to make it right.