The divisions were cut on the pattern using a 60 degree v-bit cutter. After cleaning up and drilling the holes in the casting, I filled in the divisions with a sharpie and then sanded the outside of the part to clean it up.
Here is the handle mounted to the lathe. I still need to make a pointer, but it should work fine. The divisions are set up so that 1 mark equals .001" off of the diameter (.0005 off the radius) of the part.