I was getting some parts ready for plating and decided I would redo the wing nut. Afte a bath in evaporust I noticed a ring of Zinc Dichromate plating on the square nut in the center of the wing nut. So I took it out, out of curiosity, and this is what I found. Is this how most people detail this piece? Zinc for the wing nut and ZD for the square nut?