Using a great guide on how to carve a guitar top without building 5-10 different sized templates (Link), I set about building myself a Sawdust Maker. Here it is ready for action. The router and the box are heavily bolted to the table. However the 2 pieces of 4mm MDF flexed too much, next time something more rigid.
The theory is to cut a series of steps as a guide and then smooth off with a violin finger plane.