Those tires are heavy and make great counterweights. My MOG was only a 404 (20 inch steel rims) not a 1300 but I still couldn't lift the tires by myself. Luckily the spare was lifted into position with a winch under the body. Even so I had to use a jack to get it in place under the winch.
I really wanted one of those vehicles, they can go 65+ on road.