I saw the unusual shape, dimensions (9 3/8L x 1 1/2W), and the mention of a barber's estate in the description, so I figured I'd roll the dice. See if you can guess what it is in the before pictures:



It was considerably dished out on the right side (when holding the handle) so I assume the barber was a righty and used this stone often. unfortunately I had to remove quite a few years to get it completely flat, but I still have a 1/4" on the right side and 5/16 on the left which is protruding above the handle.