It may be caused by plating, however it does 'eat' away the metal. When pieces are pitted like this, some are rather deep. As an example, if you look closely along the bottom edge, a small piece is missing (to the left of the red paint). That is from pitting, not a ding.
Last edited by Speedracer; Wed Jun 17 201502:31 PM.
-Steve B. (WTB: 48" Flying A button, 48" black/org Phillips 66, White Star, and Chevrolet Signs. Also looking for a Wayne 866. Send a PM. Thanks.)