We have a Cast Iron Vintage Salvage.  It is black and from the top to the bottom it measures about 8 3/4" x about 6 1/2" wide.  I believe it had a wall mount where the pin 2/3rd of the way up on the left sat in.  On the opposite side it is missing another piece as there is a small 1/8" whole in a flat top that a pin would fit into.......  There is a small amount o rust on this piece.

Cast Iron Vintage Salvage