British Empire - Day 6

1916 1/2d green in vertical pair with one without overprint variety, affixed to OHMS cover with the rest of the set tied by Field Post Office "G.X." 1 MR 16double circle ds, sent by the well-known philatelist H. Pirie Gordon from HMS "Exmouth" with two censor cachets, addressee excised, a showpiece item with the set and rare variety (S.G. S1b £3'000 off cover, and used set £3'500).