20¢ light ultramarine, double impression (515c). Right margin vertical pair, original gum never hinged, natural straight edge at top, natural gum creases, bottom stamp natural perf dimple, bright and fresh, Fine (photo). $2,500

A MOST STRIKING AND RARE ERROR, WE HAVE SEEN ONLY TWO OTHERS: A PLATE BLOCK AND A SINGLE CERTIFIED BY THE PF.

Expertization: with 2018 P.F. certificate. Scott $2,500 (Image)

Scott $2,500

$1 deep brown (518b). Beautifully centered, rich true color, light cancel, Very Fine, scarce this choice, used (photo). $1,250

Expertization: with 1991 P.F. certificate. Scott $1,250 (Image)

Scott $1,250