OH: I am happy to report, my wife suggested I try some Renaissance Wax on it, to see if it helped to remove the mark. When I did, I realized the mark was on the wrong side, for the divider to cause it [bottom/down side]. Then looking closely, I realized it wasn't a mark at all, but was a pattern of the grain, in a slightly different shade and texture. Mystery solved. In the immortal words of Emily Litella, [Gilda Radner] on SNL in the late 70's...Nevermind!