Auction 309-320 - Great Britain 1840–1841 Europe & Overseas - Day 5

1854, 2 d. blue, plate 4, lettered RC, perf 16, used on cover combined with 1855 2 d. blue plate 4, lettered GB, perf 14, from London to Paris, paying single rate postage, dated 24 July 1855, tied by London Inland "28" cancel in black, with "PD" oval in red and Calais transit dated 25 July 1855 alongside, arrival to back dated the same day, part of flap missing, otherwise a fine cover, a very rare mixed-franking cover used during the transitional period July/August 1855 to a foreign destination, probably unique. rnReference: "Mixed-franking Covers", by R.C. Simpson & K.A. Louis, MJ Publications, 2020, illustrated page 88 and recorded on page 102. Classified "Gold Standard".