I haven't done a dash, but I have done a guitar body and it took 4hrs to scan 1 side.
My thoughts are to measure and map it and put it into designer that way.
By the time you jig up and scan both sides you could have it carved.
It seems like Dick B. (or someone else on the forum) did a boat dash maybe they will pipe in.
Brent
A,B machines, PE,probe,conforming vectors, centerline, 2d,3d,stl and dfx imprt, rotary , 3.xx, Pattern Sculptor
OS X Yosemite
Woodwork is what I do to pay for my tool addiction.