STAMP DEALER W.T WILSON 1933 TIED SEAL BIRD AIRMAIL GB to AUSTRIA via BERLIN C2

W.T Wilson printed envelope with bird stamp seal on the back, tied by postmarks; By Air Mail to Vienna Austria via Berlin; KG5th 4d single franking; Sutton Coldfield Birmingham machine cancel; Berlin C2 Luftpostamt aircraft illustrated cachet in red.  Clear postmarks Berlin C2 + 2 different Wien.