I'm gluing the kerfing to later re-attach the back. This photo shows the original piece of plywood. I was originally going to do it this way and leave the soundhole but later decided to clear out and re-do those braces so I could run the birch ply all the way to the neck joint. I later routed out an area to give the appearance of a soundhole. This, I hoped, would give the appearance of depth, but also avoid a feedback problem. It ended up working out very well on both counts.