Here are some ideas of images I quickly threw together that are of the style that might work. Hope this helps show what direction I am looking at. Also, I like the idea of using a small "CYS" as a separator in the outside wheel area (similar to entry #107).
https://picasaweb.google.com/lh/photo/r5b4LCQZMlq6B6NGMceuUhaIlT8acqYHbCdPHcQ6gf0?feat=email