1860 (ca.), lot of six imperforated proof pairs on India paper, 1c. violet, 2c. orange, 5c. green, 10c. vermilion, 12½c. dark blue and 17c. black, printed by the American Banknote Company. Unitrade 6P (2), 7Pi (2), 8P (2), 9Pi (2), 10P, 11P. (Katalog-Nr.: refers to SG 7/19)