Air Mail cover 1933 (20 July) "PAR AVION" envelope registered to Peking bearing Martyrs 2c. and 17c. with Air 90 and Air overprint 5c. and 10c. tied by Tihwa c.d.s. with backstamps of Peking (22 July) and Mengtsz (7 Aug.) c.d.s., fine. Ex Starr. Photo