I do this not because it is easy, but because I thought it would be easy.
If I'm being honest I knew this was going to be challenging. I traced, scanned and imported the outline of the back into Vectorworks and cleaned up all the lines before exporting the dxf file to Alphacam to apply the toolpaths. I glued up the new material from Quarter sawn White Oak and cut out the bulk on a CR Onsrud panel pro router. There was a bit more post processing than a had wanted but I was able to achieve the look ii wanted with a few hours and a carving chisel. I added some Gilsonite tinter to the varathane walnut stain to really darken the grain lines. In the end I'm pretty happy with the results of remaking this broken back on this chair for a friend.
As I received it
