Another photo of the NYP DM895. It weighs in at 37,800 empty.
8 spoke 80k rears on walking beam and 23k front. Even weighing in at nearly 40 grand it can still carry 30 tons in the box, and that's sticking to the specked weight limit. I can imagine those beasts hauling quite a bit more in their day and not breaking a sweat. What ever you could get away with.