1909 Balboa, 1c dark green and black, center inverted, used, strong colors, centered to top as often, closed tear and faint toning at bottom, still fine appearing, one of only seven used examples reported, certainly among the most important stamps from Panama and one of the rarest inverted centers in the world, ex-Dr. Ernesto Arosemena, cat. $7500 (Cat No. 197a) (Image)