Canada Sc #108var (1930s) Eckerlin Rotary Intaglio 3c Admiral “Essays” Imperforate Set Mint

3c Admirals in red, green, black, and blue, reverse impressions, prepared by Dr. Eckerlin to demonstrate his rotary intaglio press which he proposed to the American Bank Note Co., never hinged, all four left margin singles, an ideal set for the specialist, very fine.