It was a good challenge to shape this board and I knew I would need to make a sanding block to help me out.
And this is what I came up with a large dowell with 60 grit emery cloth glued to it. So I taped off the shape I wanted and just ran this around the edge.
Came up pretty neat and tidy. I measured the depth on each side to get them the same as I went.
It all flowed pretty well and the finished shape foiled out really well balanced.