Willys kit: This wrench is 3 ½ inches long. It has been stamped from a piece of 3/16 inch flat stock. It is painted but looks like it may be cadmium plated under the paint. It has been stamped WO-A5130 on one side only.
Other Varieties (which may or may not be correct for the jeep): I have seen a photo of this tool with GPW and a part number stamped on it. Another tool had the 41-W-1596-125 number stamped on it.