I volunteer at a farm that has a very old Gator 6X4 with a flat tire. The flat is on the rear and the tire, at least originally was tubeless. In the pic is the valve stem a stand alone stem or does it look like it is part of a tube. I showed this pic to a buddy and he said the rim might be made special for low-pressure tires. Any thoughts on that issue ? I have broken down large tractor tires so I have an idea how to fix it. Any thoughts how hard or easy this will be to fix?