24c Green & Violet (120).
Rich colors and proof-like impressions, used with horizontal pair of 2c
Brown (113), small nick in bottom of right stamp, tied by circle of
wedges cancel, pair also tied by red "Boston Paid May 31" (1870) circular
datestamp on cover to Buenos Aires, Argentina, red crayon "24"
credit, red London transit (Jun. 13) also ties stamps, clear strike of
"Buenos Aires C. 22 Jul. 1870" receiving datestamp on the face of the
cover, reduced right edge simply repaired with small strip of paper (not
affecting stamp)VERY FINE APPEARANCE. ONE OF TWO RECORDED 24-CENT 1869 PICTORIAL COVERS TO ARGENTINA, THIS BEING THE ONLY 28-CENT RATE VIA BRITISH MAIL.
Illustrated in Brookman book (p. 181), Rose book (p. 33) and in color in 1869 PRA Census (p. 137). With 1973 P.F. certificate (Image)