Air Mail cover 1933 (August) "Hamburg" Balloon Charity Flight at Bunzlau, an interesting group of the semi-official labels comprising 30pf. red on white essay of the frame design only, issued red on white label (3, two with broken "D" flaw) individually affixed to commemorative postcards, red on blue (2) on similar cards, black on blue (2, one with broken "D" flaw) again on similar commemorative cards; all cancelled by special c.d.s. in blue. A fine assembly. M.21a-c/aI/bI, DM.7500++