Seeking repair advice: The hitch pin guard to my instrument (which is a Marxophone, structurally similar to an autoharp) has pulled off. A vertical crack had developed where one attaching screw goes into the hitch pin block, allowing the screw to escape unnoticed. When I, unawares, picked up the instrument, putting tension on the guard, the second screw pulled out, bringing a bit of wood with it. How to repair the crack and to reinforce the second screw hole so I can reattach the guard? Thanks so very very much!