Lot 1022 Canada #CL21b June 11 1927, Sioux Lookout to Red Lake, franked with slightly descending of CL21b, on back (with Type D overprint in violet), originating in Toronto on JUN.9.1927 (datestamp tying 2c green Admiral on front), with JUN 11 Sioux Lookout receiver on back, along with JUL 1 Red Lake receiver tying CL21b. A rare cover, as only 16 stamps were printed with this overprint, probably not many were used on cover, and very few were used in period (most CL21 stamps were used in March, 1928 by Patricia Airways Limited). Very fine and first time on the market, from the Armstrong find. Unitrade CV$4,000.