The year of a Massey Ferguson MG-34A can be determined by looking for the serial number on the engine. The serial numbers for the Massey Ferguson MG-34A are typically located on either the side of the engine block near the carburetor or near the oil filter on the side of the engine block. Once the serial number is found, it can be used to determine the year of the engine by accessing the Massey Ferguson database and entering the serial number in the appropriate section.