I found what I believe is a vintage organ pedal.  It is metal/steel and the word "Organ" is raised on the top of the piece.  It measures about 7 1/4" x 3 1/4" W.  It is almost completely covered in surface rust with a few spots of paint here and there as seen in my photo.  The center  is raised. 

Organ Metal Plate Question Pedal Vintage