cover 6kr. Prussian blue, a rare horizontal strip of three, fresh on 1865 (18 Sept.) entire letter from Freiburg to Sheffield, England "via Ostende", cancelled by double ring d.s. and showing boxed "P.D." in red adjacent and "MAINZ/ 1992/COELN" T.P.O. h.s. and arrival c.d.s. on reverse; vertical crease at left affects last stamp but does not detract from the visual appeal of the fine exhibition item. Possibly the largest multiple of this shade existing on cover. Ex. Yardley. M.19b. Photo