Here are some examples of the clam shell box made in leather.

Below is a composite showing a clam shell box made to hold a box which contains letters written by artist M. C. Escher to his biographer J. A. F. deRijk.  I used a print of Escher’s own work for the inside lining.

This box was made to hold an old family Bible that had fallen apart.  Customer provided fabric to use for the inner lining.