Custom Manufacturing developed a range of tractor models after World War II, utilizing Chrysler engines and transmissions. They manufactured tractors under the Montgomery Ward, Lehr Big Boy, and, in Canada, the Rockol and Regal brands. Established in Shelbyville, Indiana, in 1944, the company was sold in 1952, leading to a relocation of production to Hustisford, Wisconsin. This operation continued in Hustisford until 1954, when the company's assets were acquired by a Mexican firm.