Great Britain 1840 1d intense black Plate 1a, SG1First day of issue of the penny black cover with deep black impression including letter with important philatelic historical content. Great Britain 1840 1d intense black Plate 1a, SG1. A very fine used large four margin example neatly tied to small clean cover by a red Maltese Cross with an octagonal London datestamp on reverse for the first day of issue 'MY. 6. 1840'. The cover was sent locally within London and comes complete with original contents