That's not a Ford PN. A Ford number prior to the change to a standardized number (supposedly happened some time around 2000 IIRC) should start off with a decade letter and then a year number. 1987 would be E7. 1991 would be F1, and so on. The next two characters are the vehicle code. ZZ is the code for the Mustang. There's a good chance that the window motor does not carry a ZZ code as it is not Mustang specific and was probably used elsewhere before that.
I'd bet you got a knock-off. I don't know that the motor would say Ford on it... I don't have one here handy. The only one I have not installed in something is 20 miles away.
JS