The prototype of both cars was built by the American Car and Foundry Company for Sid Richardson Carbon Company (SRCX), Columbian Carbon Company then Columbian Chemicals Company (CCX) and American Car and Foundry Company (ACFX). This HO Scale 1:87 ACF 4589 Cubic Foot 3-Bay Carbon Black Covered Hopper Pack STL files comes with 2 version body styles, roof, logo board for Columbian Chemicals Company, brake wheel and coupler box covers. The only thing that you need to complete this model is some 70-ton or 100-ton rolling bearing trucks with 36' metal wheels and metal couplers for the era of your choice with these cars. Also you need 2-56 x 1/4 phillips pan head screws for the trucks and 2-56 x 1/8 phillips pan head screws for the coupler boxes. Note these STL files is for personal use only and not to be commercially reproduced!!!