The serial numbers for the Cockshutt are mixed in with the Oliver serial numbers, Since you mentioned your tractor was going to need some work you may want to look for a year and a number stamped in the top of the cylinder head in the front. Some are under the thermostat housing some other the edge of the valve cover. This will be the month and the year the head was machined. There appear to be quite a few 1948 model 60 tractors.