The cutting of the groove in the leading edge of the center-board took only a few minutes. I clamped the center-board vertically against the workbench and ran the router with a straight bit along the edge. Then I filled the groove with thickened epoxy. While the epoxy cured, I laid down the two long fillets along the keel.
To shape the center board’s leading and trailing edge, I started off with a sharp hand planer followed by the ROS with #40 grit. The leading edge and the bottom should now be sufficiently protected against unwanted contact with stuff that is not water.