We have a vintage cast iron rusty (fully rusted) bracket.  It measures about 7 1/4" x 6 1/8".  The very base of the 7 1/4" side is broken off at the bottom where the final screw should have been.  There are places for 5 additional screws on the bracket.  The back corner measures about 1 1/8" and it narrows towards the end to 5/8" in thickness on the top.  I would consider this in fair condition.