Classic Machines TractorsClassic Machines: The Oliver OC-18 tractorContrafed PUblishingDecember 8, 2015November 20, 2019 by Contrafed PUblishingDecember 8, 2015November 20, 2019 In its heyday, the Oliver Corporation of Cleveland Ohio, USA was a well-respected company manufacturing agricultural tractors and implements. By Richard Campbell. Looking to expand...