It's looking like a bow now. I've rasped the corners off the belly, slimmed the tips and eased off the outer half of each limb. The pics show the central pith, the remains of the nasty knot and a small pin knot that I filled.
Where the central pith disappears into the thicker section near the grip there is a very thin layer of wood over the pith, this may well crack or buckle, but hopefully it will be worked down beyond the pith by the time it's finished. Any cracks will be largely cosmetic anyway, to help avoid this I've flooded the pith with low viscosity superglue.
The main pic shows the tiller 100# at almost 24" at a low brace.
Since then it's been eased off more and the brace height increased, it's now 100# at 26" at near full brace.