Corey- Here's a method I've been using: First, pick a tallywacker style bait that runs well to use as a model. This will keep you in the ballpark as far as functionality is concerned.Slide the fin into the slot you cut in the rotating tail section, and draw or scribe a line along the fin where it meets the tail. This will give you a reference point to help you determine where to bend the tail to match your model. For sharp, angular bends,(like the fin on the Buchertail Top Raider) I put the fin in a vise between two pieces of oak, and bend it over the edge of the wood to the desired angle. I bend by hand and use a ball peen hammer when I need to. For curved bends, I bend the fin over a steel rod secured in a bench vise. Put the fin back in the tail and compare it to your model. Repeat the process until it matches the model. Then epoxy the fin into the tail. When the bait is done, you'll need to fine tune it until you get the sound and rotation speed you want. I use needle nose pliers (with tape wrapped around the jaws to reduce marring) to fine tune the fin. I'd love to learn how others do this. I'd like learn a better way!
Rollo