get/find a thick wood plates. Cut to size or two halves. Chop-saw is your friend.
laser-engrave wood
lacquer wood
optionally assemble two halves of wood with hinges
3D Design some feet for board
3D print feet
Size and scale board and stones
3D print stones
3D print bowl for stones
I scaled everything, board, stones (and grid) to fit small stones 17.91mm in diameter and 8mm in height.