There are an infinite number of lines that can pass through two points, and an infinite amount of ring shanks that can be designed.
Imagine a single half round shank. A half round shank, but split the ends for better support of the top face. How about two half rounds soldered together in the middle and splayed on the ends to attach to the top? How about two half rounds with a twisted or braided half round in the middle, or . . .