[Jason in TX]

Here is a Model A era desert water bag in my collection that I bet you've never seen. It's a desert water bag around a galvenized box that was meant to clamp to your running board. You put your food in the box, close the lid, pull the cork and fill the flax bladder around the box with water, and drive away. The evaporation cools the water, and in turn, cools the contents of the metal box. The brochure advertising them is from 1928 or 1929 and I've only seen two others, one being in a museum. Note that the drain for the bag is just like the drain petcock on the lower radiator hose of the Model A.