I own a 1961 MF35 tractor (Perkins Diesel, 3cyl). S/N SNM210856. The engine S/N appears to be GKN1523G. Does anyone know where I can find the system MF/Perkins used for the engine S/N on these tractors so that I can definitively determine specs and parts for the engine? So far I have been unable to find any information on what these serial numbers mean or any cross reference to specs. Thanks.