Les what you are talking about is called veining. There are several ways of doing this. The most common is to drill a small hole and insert a thin scroll saw blade and cut that line. Some will use a flat blade such as a #3 or #5, some use a spiral blade such as a #3 or smaller. A lot will depend on your skill level and patience. Basically Les, drill the eyeball, cut the eyebrow, cut the leg veins. Nice job on the puzzle btw. Thanks for sharing this with us.
DW