Sweet! Good idea with the Forstners; I figured it would require routing, but going to an irregular surface with a bit moving that speed seemed... tricky.I did. It wasn't too hard. I used my drill press and a set of forstner bits of various sizes to cut out the basic shape and then finished the edges with wood carving tools. It took me about a half hour.
I need to go back and deepen it about an eighth of an inch to bring the copper custom brace adapter flush with the top of the stock.