Or maybe ones with, and without the hook were being produced on different production lines at about the same time in the late 80's, and some came from the factory with the indication
How many production lines were running concurrently in 1989?
I think you are right in your analysis,I don't think this label is posted on the dealer's back.Because the number and model on the back of the box are printed.It is consistent with the label on the side of the box.Maybe your knife is a product of different production lines.But what interests me most is the number.Did they create a new number for the hook?