Welcome to the board.
Chances of a "factory error"- zero. Someone put it on because it was "close"; guys try all the time to match up their parts, problem is even if the last two digits are the same, it is still quite likely not the "original" part.
If you want to tell us what you have "in" it, someone will say good or bad!
You basically have what would be a "shooter", if it shoots well.
