Hi Charlie. Have you already tried drawing the spiral outlines? Seems like a pretty straight-forward procedure. (Draw ellipses, add lines/curved, cut where needed, etc. )
I guess you could start with a Spiral using the Spiral gadget, but you are going to have to edit the vectors anyway, to match your Bitmap photo guide. Six one way, half a dozen the other.
-ShopBot Buddy PRSAlpha CNC