Slide Picture Puzzle Box

Solve the picture to open the box. (This is a physical kit. Please see my other listings for the digital plans) We have all toiled over these slide picture puzzles as kids, only to find ourselves stuck with one little piece impossible to get into the correct position without undoing all of our hard work. As an adult I feel I have finally put this conundrum to rest and have discovered the secret method. I then set about designing a secret box that can only be opened by solving one of these engaging little slide picture puzzles. Here is the result. The secret method is etched on the wall panels. The image to unscramble is Leonardo Davinci's famous Vitruvian Man.