Well, I recently had to do another one, and this one was to replace a whole rosette with another AND also the spruce in between rings. I had used cyano to glue in the center inlay and it turned the spruce yellow. I thought that I would have to replace the top, but gave a replacement rosette a try first. Here are the photos. My first thought was to leave the outer ring and that was a mistake. I didn't document the whole process, but the essentials are there. As an afterthought, I probably would have cut half the outer ring and put the new seam for the spruce plug there. I missed perfect fit of the plug by a couple thousandths and cut a little off the outer ring. so I had to make it B/W/B/W/B.
I was fortunate in that I always use a full crossgrain doubler under the rosette so that I could rout right down to the doubler. I glued the routing plug in with a few dots of cyano after rotating the plug to find the spot that would leave the outer ring intact. The new plug of red spruce was matched to the grain of the old as closely as possible and made of two pieces so I had the center seam and also the slight amount of run out to match the top.
A block support was added to the new plug and it was glued in.
Then I was able to rout a whole new rosette. Originally, the outer ring was intact, but I lost a few thousandths somewhere with the new plug.
After the new rosette was in, I resanded the whole top.
Hindsight being 20/20, I wish I would have hidden the seam under the outer ring and just routed the ring over again, but it turned out pretty well, and I decided to keep it as is...
