Here is the finished drawing. I blew up my thumbnail, transferred to marker paper. And did this with prismacolor greyscale markers and a .25 pilot hi-tec c pen. Also a little bit of pencil to help lay out a few of the tighter details. Pilot hi-tec c pens are my new favorites. I stumbled upon some in Indonesia this year. They are made in Japan, and hard to find here in the US. There are a few websites that carry them, and a few stores here and there it seems. Mainly in Japanese stores.
The image above is about screen size when clicked on. The lower image is 2x the size when clicked on to show more details. I drew this at about 24 inches wide.