Looking at the image above, of the off side of the rifle, it occurred to me that to a novice builder's eye, there is a cove cut all the way around the lock, and that may be why we sometimes see that treatment on rifles posted here for critique.
This is of course, not the case at all. As an explanation, what you are seeing is a relief carved panel, likely less than 1/32" deep/high, outlining the lock panel. The width of the panel varies - there are hardly two places where it is the same width, and that adds much interest to the rifle.
I hope that makes sense...