Pirate's Ship Wheel Hub

I built a tree house with a Pirate's Ship theme. It has a ship's wheel with a bolt holding it on. I wanted to attractively cover the bolt so I designed this cap with a Pirate coin as the face and the Initials *DMTNT! as a banner around the perimeter. I'll leave it to you to figure out what the initials stand for. It took my grandkids about a day to figure it out. The steering wheel cap has a hexagon shaped hole which slides tightly over standard 1/2" nuts found at Home Depot.