So, I've taken it apart. The first course of action is to get the plate attached to the plate so it is functional. Then we can discuss the rust before we start using it. Any suggestions on what should be there? Seems like there should be some type of piece that would fit up into that little block and then maybe held in place with a snap ring maybe? The screws came out much easier than expected, so perhaps someone in the past took it off and threw away some pieces? Anyone know how this is supposed to be attached?