Canada CL20b

1928 (March 9) Sioux Lookout - Red Lake flight cover in pristine condition, bearing 2c green Admiral tied by clear Sioux Lookout duplex grid datestamp; on reverse the scarce (50c) Patricia Airways, Style Two with ascending 5c overprint (Type B) in red postmarked on same-day by Red Lake split ring on arrival. A beautiful cover bearing an elusive airmail stamp, carried by Patricia Airways, Ltd., Very Fine (Unitrade CL20b)