Operating Era: 1912-1975. THIS SERIES NOW COMES WITH OUR NEW ONE-PIECE ROOF FRAME. Canadian National Rwy, Erie, Susquehanna, Grand Trunk Rwy, Grand Trunk Western, Nashville, Chattanooga & St. Louis, Erie/Wells Fargo. The first true single sheathed design, between 1903 and 1923 over 75,000 cars were built. As with any high volume production over a long period of time, minor improvements were continually made. Combined with upgrades that the different railroads made, literally dozens of different versions existed. Our 6'-door kits model 14 physically different prototypes