Canada 670-673

1975 8c Coastal Vessels; the Production File from the estate of Gordon Yorke, the engraver of this issue. Comprising nine different progressive die proofs of the engraved riggings, plus two engraved transparencies and three photographic essays. Couple with a stain, a fascinating and UNIQUE group demonstrating the production leading to the issued stamps, Very Fine   (Unitrade 670-673 proofs)