Can some one explain the differences in the variations in the early CH K Model Horse Shoe Oil Tanks? I have a couple different types. 1 type has 4 fittings across the front of the tank and a drain plug on the lower left side. The other type I have has only 3 fittings across the front and a small sump with a fitting on the lower left side. I'm trying to figure out which would be correct for a 1960 XLCH and if one would be correct for a 1956 KHK?