I know that sometimes it's really hard to see what's what in a picture, but that area along the edge doesn't look so much like wear, but it appears to be galling.
And since galling is literally the gouging out of metal on the contacting surface, all that leftover metal also suggests that it's galling and not just "wear".
I would seriously think of sending it back to Rohrbaugh to at least have them look at it because machined surfaces are supposed to wear in and mate smoothly with each other, and galling is anything but that.