Quote Originally Posted by MattKing View Post
I wonder how long it will take for someone to modify this to enable use of a focussing lens?

^ Why?
It's a pinhole camera (albeit imaginative and a notch up on many common designs). It therefore has it's own characteristics that do not rely on focusing but the formation of an image through a primitive brass shim. Making it a focusing camera will destroy its appeal. If photographers want a focusing 5x4 they would be better served buying a Wista.