These photos show the surface oxidation that happens when doing poor zinc plating, the oxidation took place over an eight year spand https://pbase.com/9146gt/image/163168380. At the time, the newly applied Zinc looked great https://pbase.com/9146gt/image/97501850, but at the end, it was simply a crappy plating process. For the next go-around, I will make sure and request a sample plating using one of my unmolested Scheel or Recaro OEM seat rails. My originals appear to have been clear-cadmium plated, not Zinc--- and even after 40+ years later, they still look great!