[rotorwrench]

The frame number stamped on the top rail just to the rear of the front left body to frame attachment, is the only official indicator of approximate date for title registration purposes. All else is replaceable. If it has a 1931 frame then it's a 1931 and so on. If it indicates September 1929 then it's a 1929.

There are subtle clues to the trained eye about approximate date of manufacture in the factory changes to frames that happened regularly during model A production but it still comes down to that VIN serial number. November 1929 was the change over time frame when production of the 1930 model bodies would have been fully incorporated. The only acception was the early 1930 pickups or commercials. All of the car bodies made the change for the new styling whether made by Ford or by the subcontractors like Briggs and Murray.