For those that want to do a CNC version (like me), here's a link to get you started with material:Interstate Plastics UHMW Sheets
Four sheets should be about right. The Ring is just over six inches in diameter and the former bobbins are just under four inches in diameter. With proper placement, you should have just enough surface for a couple of moguls and still be able to finish this project.
I will be working on a CNC version of the drawings specifically for an 1/8th inch plastic router bit--no lightning holes or tapered edges. Stay tuned...
Also, a good router bit makes life much easier. My preference is the Amana Tool 51411 available at ToolsToday