10c Black (2). Position 21R with double frameline at left, large to huge margins including left sheet margin, vivid red grid cancel, matching "St. Louis Mo. 10 May 3" (1851) integral-rate circular datestamp on blue folded letter to Philadelphia, from the Charnley & Whelen correspondence, horizontal file fold well clear of stamp and postmarkEXTREMELY FINE GEM STAMP ON A BEAUTIFUL FRESH FOLDED COVER. ABSOLUTE PERFECTION.
Ex Knapp (lot label affixed). With 2013 P.F. certificate