This came out quite well I was a bit relieved as I had struggled to see what it would look like in the lofting and had then decided to leave it to now and work it out. Phew!
Finally the blank I had left in the centre board slot could be cut out. I had already cut the side cuts but had left the blank in place to make shaping the keel easier. I made to end cuts with a coping saw and straightened up the edges using a block plane and chisel.