Yes- with a big enough lathe and several carbide cutters (I've done it and brake rotor cast iron is really, really tough!) But for all practical purposes the genuine, one-piece OEM ventillated '66-67 Mustang rotors are gone. They used to bolt right onto Panteras, but available replacements are different.
And the 1/2" OD difference between the original front & rear rotor ODs makes zero difference in braking unless you move the calipers outboard on the slightly larger rotors to take advantage of the extra leverage possible. As bolt-ons, larger rear rotors are slightly heavier if interchanged to the front but do not stop better unless modified.