Lot 40571 – 1871 (Mar 30) envelope to the USA with 1861-70 (4d) dull vermilion and 1871 (1d) blue tied by “1” oval numeral

1871 (Mar 30) envelope to the USA with 1861-70 (4d) dull vermilion and 1871 (1d) blue tied by “1” oval numeral, with ms “4” adjacent and New York Steamship 10c cds below, endorsed “pr Steamer via St. Thomas”, reverse with despatch cds, missing backflap otherwise very fine and fresh, the only known combination of S.G. 28 + 48 on cover to the US according to Peter Ford; signed A. Diena.