Polishing or cleaning to be left up to next collector. Note his earliest less common maker's mark of GS on the applied lozenge. The stone wiggles a bit, yet it is securely set. Please search # 459968 for a set by same stamped: just G. That mint set has his red green foil art glass stones. Also for his unsigned piece # 1177895. From personal hand hammering experience, the marks are not perfect and are often superimposed.