Hi! I'd say Top Latch Does serve purpose, tho this latch looks Plastic. i imagine on plastic mailbox, it could, would, should work as thought, but on Metal box, *NOT.* Metal box latch even has holes, > for Lock? Seen new metal boxes with No Top latch, they do Not stay closed! My idea, if not Hanging Box Upside down, hinge Lid at top, give Gravity a try. *8|}* _Top hinge is your design_
