All done! The rod needs one final straightening out over the fire, but otherwise it is ready for use. Hopefully I can give it a test this weekend as I am going to Kasumigaura.
The thinner parts of the rod are stored inside the bigger, and the open ends stoppered with bamboo plugs when in transport. In this state the rod is about as large as the heftier variety of fountain pen, and can be easily carried in one’s top pocket without notice. I think I am going to try to make a bamboo tube for the rod to fit in, along with space to carry line and a hook.