I did this in two stages, one tentative, and then with inspiration from our head of teaching, Bob Forsyth, I weighed in and finished the job properly.
The first stage was based on what I knew of stem shapes looking around me and left the stem head square. The second stage took me into fine boatbuilding territory and resulted in a shape that I’m very pleased with.
I’m working on a brass fleur de lis that will crown this, pictured here is a first experiment in how to do it, the real one will be much better.