Canada, Unitrade Specialized 142, CL40; US C10, used on mixed franking Cover.  Light blue Western Canada Airways CDS ties 10c black & pink Semi-Official Air Mail issue, and 2 strikes of THE PAS / DE 2 / 27 / MAN tie all 3 stamps including 1927 10c dark blue US Air Mail stamp, addressed to well known cover dealer A.C. Roessler in East Orange, NJ, inscribed Via Chicago Air.  Colorful & VF.