I did the majority of the stringing on this piece by using a typical scratch stock. The bow front presents some complications. The undulating areas are tricky. I started by making a scribed line guided by the curved edge or by a compass depending on which area I was working. Once the scribed line was in place, I used a sharpened straight screwdriver to stamp a groove.
About the screwdriver: I bought a few straight blade bits (longer ones I could hold). I dressed them with a bench grinder to the desired width and with parallel sides. Then I carefully cut a "V" parallel to the sides in the bottom of the blade leaving 2 sharp edges.
On to the stamping: Catch the edge if the bit in the scribed line and with a light hammer shot drive the material inward slightly. Repeat the process and walk around the curved parts a 1/4 inch at a time.
I've probably made this as clear as mud. If this is anything like you're trying to accomplish I can elaborate further.
I believe I "borrowed" this process from Jeff Headley.