An update: I made another one today. The threads on this one were much smoother, the ones on the first one I made definitely have a problem.
Like hard hat said a couple of replies back, the finial screws into the end cap, all one piece. Can't find my metric thread gauge, so I can't tell the stud size if you want to make your own finial.
I like the kit better now that I made one with better threads.
-gary