[A 2 B]

Just my opinion, but I believe it is a question only answerable by the jurisdiction that makes the laws and will surely differ state to state. Ford may have had their system of assigning identification numbers but certainly were not the legal authority after the sale. Federal regulations were firmly in place after the V.I.N. system was instituted but previous to that a lot of wiggle room and discretionary decisions were obviously made by individual states and their employees.
It leads me to believe that, previous to V.I.N.s, the person who had their name on the title was free to sell all or any component (engine, frame, body) along with the title, simply because all parts are replaceable.