The daggerboard slot emerges from the keel at approximately the width of the keel, so it is necessary to sister the keel on each side at this point. I somewhat arbitrarily chose a two foot span... about 6 inches fore and aft of the slot, tapered back to the running width of the keel. The keel and sisters join in a simple a planed joint, but the surface where the sisters meet the hull is a winding bevel. I spiled the shape of the hull onto a pattern, transferred it to two blanks of Alaskan yellow ceder and cut them out. I then found the bevel on each end of the blanks with a block plane, and used a sweet little Japanese wood block plane with a convex sole to render the winding bevel between the ends. The gap-filling properties of epoxy peanut butter reduce the demands on my craftiness (copious squeezeout is my friend).
I free-handed a gentle S-curve taper, bandsawed the curve, smoothed it with the stationary belt sander, mixed the peanut butter, and clamped the whole thing together. Cutting the slot through the keel and final shaping are all that remain on the keel punchlist.