My guess is that those are 7.50x16 size tires mounted on factory split rims. I still run that size remington traction tires that came mounted on my splits but will replace them eventually with 255/85/16 radials which work out to be 33x10x16's. Check out @JohnnyC 's white cruiser for a visual of this size on a 40 series.
That size is extremely popular over here in Papua New Guinea, but most people run Bridgestone Jeep Service tires (tube type, bias ply and on split rims) which look very similar to the Lima Conchos. Over here, running on mostly under maintained dirt roads that occasionally turn to mud, the locals consider them to be better performing than any other available tire. I have to admit that they do seem to work surprisingly well. We don't have sand over here so can't tell you how they do there.