Ok Adrian, it's done! I'll get it in the mail Monday.
This is to fit his aluminum Rob Allen tuna barrel. The band holes are 9/16" diameter, and the shark spike is 9/32" diameter by about 2" long. Just a simple 1/8" pin on top for the line wrap, and you can see how I did the bottom line anchor.
The design may look overly simple, but I kind of like the "no nonsense" look. It was also partly an experiment on my part to see how practical it would be for me to make more if there is any interest. As it turned out, the line anchor is by far the most aggravating part.
Oh, and Adrian. It's a nice, snug fit. So get it lined up right before you tap it in because you don't want to take it out . . .