I got the patch glued up yesterday so it was ready for rasping down this morning.
To help saw the patch out I used a big round steel clamp that I have lying around (part of the packing from my dust extractor) you can see it in the pic and it acted as a template for both the scoop I rasped out and the patch. it gives you an idea of the actual shape. I have seen people use the round nose of a belt sander to shape the scoop, but to my way of thinking that is far too small a radius as gives less glue area. I have no real evidence for that, just my gut feel, any comments or experience would be welcomed. I used the usual Resintite glue and plenty of masking tape to protect the rest of the bow limb, especially the sapwood... don't want glue all over that!
Enough chat, I'll let the pics do the talking.
In the final finished pic you can just see where the grain swirls around where the pin used to be. So the plug of the knot hole is now solid and embedded with in the bow underneath the patch... hopefully that should stop it pinching!