I just got a new camera, so to celebrate, here's a pic of the mystery hone. To recap: dimensions = 9" X 2". From a co-worker in his fifties who says it belonged to his wife's grandfather. Pretty soft; flattens easily on dry sandpaper. Fairly coarse & aggressive (finer than 1k sandpaper, coarser than Cushioned Strop barber hone). What is it?