Thanks for the post.

Just one (very small) point. It's difficult to see from the photo's and there may have been other reasons I can't see, however IF the grain (green lines) is/was what it looks like, I would have been really tempted to carve it to the red outline. While it's nearly impossible to buy thick C-grain wood to carve into a control surface, sometimes you can get closer to C-grain by choosing which side of the stock to carve. If I get a nice piece of C-grain I try to carve both sides.