[rotorwrench]

That method would only have accuracy if the cars were assembled at the same plant. Bodies and body parts as well as engines & frames were sent out to branch plants in limited quantities depending on rail road or shipping capacities at the time. Complete assembled bodies were shipped all over the place as well as the components to build up bodies. Some branch plants were limited in what they could fabricate & assemble so they needed more complete bodies and then others even had limited stamping capability along with near full assembly capability. Most of this info about the branch assembly plants is available at the Benson Ford Research Center. Ford didn't build up the fordors but they needed to sell them in all the different dealer agencies so most of them were completed bodies shipped out from Murray and Briggs to all the locations needing them.