Unusual well crafted folding checker board

Really cool 16x16 board with brass hinges, hasp and screws. The hinges an hasp are inset into the wood. Made by a skilled woodworker, not furniture maker. Inlaid checkerboard on top of plank. 6 troughs, 4 are similar in size and 2 are tin lined and shorter in length. troughs all line up. The large troughs appear to be to accommodate checkerpieces. What are the tin troughs for? There are no cigarette burns, so not ash tray.

Duck head is 1890s iron and brass paper clip. The mallard head has glass eyes.