I was going to say that a coin counting/rolling drilling machine could cause the SCRAPE, but not on both sides at the same time, only the last coin side showing at the top of the roll would get the mark. Can't say what could have caused the marks, most likely PMD.
Can you weigh it?
That will tell us whether it is zinc. It's possible a caustic liquid dissolved the copper in the lower areas around TRUST but left the tops of the letters intact.
The white powdery substance if front of Lincoln's face looks like a leftover residue from a liquid.