Backup lens, did the design change? 1959

[Lorkowski]

On the 1959 backup light lens, the ring where the 3 screws mount the lens,
In my car, and several used ones I’ve seen, its chrome. But on the repro ones and even a nos one i acquired, that ring is black, while the rest of the edge is chrome.
Did anyone else notice this? Its there a reason?

[droptopford]

I don't know if there were any differences in the design. Mine are original. They appear to have had black around the ring (where the 3 screws are) and a thin layer of plastic 'chrome' around the edge. Some of the black remains as well as some of the chrome, but most of it has faded away.