Just a quick warning if you don't already know: IH start on gas diesels are expensive to repair, just fixing a cracked head can be around $1000. Also, main bearings are VERY difficult find for those engines also.
As for the serial number, I am guessing the V is actually a W. In which case the W12B suffix would mean Pnuematic tires, swinging drawbar, electric starting and lighting. Serial number shows up as McCormick-Deering WD9 and the year would be 1951.
Hope this helps. Info taken from Guy Fay's "Farmall Letter Series Tractors"