1921 Airmail set of 5, each value tied to separate cover by Tientsin 22 May 1923 cds, and each with large boxed bilingual cachet for flight into Peking, each bs, some with add’l franking, four covers without top backflap else fine and scarce set addressed to Sino Italian Bank (Mü 5a, 2’500 pts each) (Image)