Hello Dan,
Page 70 of Firearms, Traps and Tools of the Mountain Men shows a somewhat similar touch mark. At least it has three similar circles. The caption in the book describes it as a french ax. I once had a trade hatchet shaped similar to yours and believed that the shape (missing top edge of blade) was probably due to some particular use to which the ax was put. However I won't even try to guess what that use was. . . . Rod