Folks: Found this article on construction some automobile box cars. I think the aforementioned series is possibly correct; I've put the Frisco Employee's Magazine article of September 1930 below and will try to get the official register data compiled. NEW CARS COMPLETED The last of 230 new automobile cars were completed at the North shops of the Frisco Lines in Springfield, Mo., August 12  and place in service immediately. The building program on the 230, 50-foot single sheathed, steel frame cars began April 1, and 200 men have worked steadily to produce the cars at the rate of four and five per day. They were completed at a total cost of approximately $600,000. An unusual feature of the cars is that they are equipped with end doors, as well as the regulation 12-foot side doors. The end doors lend greater facility in loading and unloading automobiles.