These are contour plots of the plates of a violin and a viola da gamba. The viola da gamba has a flat back so only the top is shown. The contours are like a topographical map of the surface.
I hope to use these plots to make templates enabling me to use a Saf-T-Planer in my drill press to rough out the general shape of the plates for final finishing by hand. I am not to lazy to do it by hand from scratch, but I find I spend a great deal of time doing very careful carving in the last few millimeters. I tend to be too careful, so I hope to speed things up and get to the interesting part faster by enlisting the aid of my drill press to do the less interesting but no less important part of the work.
This is not such a big leap, most makers use the drill press to rough out the inside of the plates, saving themselves a lot of work that was originally done with a gouge and toothed, round bottomed planes. (The planes themselves were designed to make the job easier than using the gouge alone.)
I used techniques learned from boat building to develop the contours from the very basic sections that were provided in the original plans.