re: right side grind?
Based on your pictures, the left side was ground first, then the right side. I believe the right side of the RAT ground, in your picture, is the deeper grind. This supports what I suspected in my post below.
Us one-eyed people who see the world in 2-D can spot these kind of things :) For us, a picture looks the same as the 3-D world.
Here is the latest NASA press release