I have a '86 XJ6 I'm appraising. It has conflicting VIN's. The cowl tag says SAJJAVLN4GC444094 (or 054, it's illegible) and the door sticker says SAJAV134XGC444054.

CarFax says the cowl tag is invalid and that the door sticker is good. I know how to decode these but I don't understand why they are different. Can anyone enlighten me please?
Thanks,
Wayne