One of the old wrenches I have is interesting.
The box end is 11 MM, it has a clear 11 (mm) stamped on it. The logo is a M inside a circle. The open end is much bigger than 11, likely 19 or so.
I have always wondered what type of Ford wrench it is. What car did it come with or what car was it made for?
It just hangs on a nail in my garage as a display piece. Next to mt timing light, dwell meter and hand operated drill, brace and oil can spouts.