Can someone tell me what the purpose of the square metal/aluminum piece (about 1" square) that is attached to the leading edge of my 82 Catalina 22? It rests on the transom when the rudder is installed. I cannot figure out what is the purpose of this block nor if it is a standard part of the rudder. All I know is that it is damaging the top portion of the transom where it rubs against. Thanks. Chris