While out for a drive on some local backroads I stumbled onto a tractor for sale. I checked it out and found it to be a 1950 Case VAC with duals. I've searched the web and can find no information on the VAC being produced with duals. I found a picture of a 1951 SC with duals however. Were duals a factory pruduction option on any Case tractors, specifically the VAC, or are the duals a custom addition? Is this some rare version of the VAC? Does it have any additonal value due to the duals?