1973 duster door tag sticker

imagine that...got no idea then good luck.. my original paint 73 340 duster came with a 318 vin number sticker on the door and its a real h code 340 car had the original b1 blue paint on it so either someone replaced the drivers door with the same original b1 color door off a 318 car or someone at the factory stuck the wrong sticker on it. the car was a original paint south Carolina car and no signs of ever had any collision work done to it n haven't checked the date on the fender tag to see if it matched the door sticker but I will today just to satisfy my curiosity..