I might have made a mistake, but not a big problem, Mine had a assumed "yellow dichromate" tint to the Galv spangled surface so I took the easy way out and just Zinc Dichromate plated them (Restoration purposes) you loose the unique galv spangled appearance - compromise. Really when installed you do not see much of it.
I would assume, the sheets that these were stamped from were pre treated or they were hot dip galvanized after the fact.
My 68RS had one of each, but now that I think about it, It suffered a previous Owners girlfriend and a ditch and a line pole, so service bucket might have been installed (Black).
Jim