The Ursus C-451 was a popular model of tractor, manufactured by the Ursus Factory, based on the German Lanz Bulldog D9506. Production of the original model, the C-45, began in 1946, and was replaced by the improved C-451 in 1954. Ursus discontinued the model in 1959, and the design was then sold to Zakłady Mechaniczne in Gorzów Wielkopolski.Photo: Łukasz Golowanow & Maciek Hypś