1937 (15 Feb) large part cover to Johannesburg with 1933-41 20c Slate-grey (partly torn away) and 1e Claret strip of 3 tied by Lourenco Marques hexagonal ds, vertical creases and some soiling. Carried on the emergency airmail by D.E.T.A. to Johannesburg following severe flooding which caused disruption to the rail service. Rare, with only six commercial items said to have survived