A12 yes that is the style of the original wing nuts in your picture. The interesting thing is that the 4 bbl wing nut attaches to a larger diameter stud while the 6 bbl wing nut stud is smaller in diameter. Also as shown in the factory diagram there wasn't a washer under the wing nut on the "shaker" tin.
Wish I could find the thread that went on forever about these wing nuts. Anyone have that?