I'm gearing up for a semi hollow archtop build drawing inspiration from vintage Hofners (not the violins). how does one get that characteristic shape on the surface on the top and back. My plan is to make the body as I would a standard solid body and route out much of the innards then glue the top on. how might I get that shape in the top? The back isn't as big of a concern to me, but I would like to shape the top.