I started out by making a blueprint of the hammer head, so that I could size it out to the staff I was going to use.
For this, I made the back and bottom piece to the shape I wanted, then attached them and used the opening to trace the shape I needed. After that it was a simple thing to cut it out and give it a slight curve with the heat gun, though gluing it was an absolute pain.... Got those on, traced and cut a hole for the staff, and hot glued that right in!
Thanks for reading! Enjoy some final pics of it and the rest of the pile I took to Anime Banzai!