For what it is worth, here is an enhanced blow-up of @cus' first picture. The pixelation makes it hard to know for sure if it is a die chip or damage, but I agree that there is some underlying zinc core visible.

"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz