Heel, I have 4 ignition wrench sets for sale on the bay, Bonney - Vlchek - Duro-Chrome - Blue Points, that include that size.
Cant say that I ever actually used one myself...
I do have a drawer in my Gerstner tool box for vintage small wrenches, smallest is a BluePoint C1514 7/32 x 15/64. 2 1/2" long.
I like the smalls !!
Brian L.