This is most of my collection. I bought a "new" 13 mm in the late 80s or early 90s as so often I needed two 13s at once.
I also have a set of these. My dad bought them in the 50s and he called then carburetor wrenches. The 1/4 inch one came in really handy once when removing a screw into plastic that had almost no access.
I have them down to a 5/32. There is nothing on the back at all, and they don't have the raised bar of the front. The 15/64th side is not often needed!
