Lot 51785 – 1860 (Apr 28) envelope to the USA with 1859 imperf. 1s indigo and 1854-57 (1d) rose-red

1860 (Apr 28) envelope to the USA with 1859 imperf. 1s indigo (just touched at top left) and 1854-57 (1d) rose-red (3 margins, surface abrasion), both tied by « 1 » numerals with « PAID / AT / TRINIDAD » crown circle hs, reverse with despatch and St. Thomas DWI transit, San Francisco cds and « 20 » struck on arrival, some cover wear, still a rare usage of the 1s, with the WIPSG census recording only 9 covers.