Canada, Airmail Semi-Official, 1926 (25¢) Patricia Airways, "Red Lake" Inverted Ascending Overprint, rouletted, type D overprint, top stamp in vertical pair with no overprint on bottom stamp, o.g., margin thin in bottom stamp, otherwise Very Fine, still a very rare combination pair, unlisted as such in both Scott and Unitrade catalogs. Scott No. CL30c var.  Estimate $300 - 400. $0 (Image)