The Helen Davis Collection of Penguins: Zanzibar: 1948 (Oct. 22) Ilford Selo Films attractive illustrated advertising envelope registered to Colorado, U.S.A. registration label tied by straight line “BY AIR TO LONDON ONLY” instructional mark and bearing 1936 values to 1s. on reverse paying 2s.60c rate, also a two-colour version of the envelope used 1950 in Gloucestershire. (2 covers) Photo. (Image1)