I spent today laying out and filing half round grooves at a 30 degree angle to the shank of the ring blank.  The grooves extend into the back of the shank as well.  I am pretty pleased with how it turned out because I was totally winging it.  I had only a vague idea of the outcome when I started this morning.  There are 9 grooves on each side of the ring.  I think if I do this again, I will do 10 grooves on each side.  Some of the grooves are not as evenly spaced as I had hoped, despite my best efforts.  I think having one extra groove will help utilize the available space better.

I think perhaps tomorrow I will get back to forging a mokume billet.  I do have some other file ring ideas I want to try out and I do have some silver ring stock to work with.  I will see how I feel in the morning.