1943, 2 zloty \"structure barbican in Cracow\", proof in purple brown (madder red), single copy of the original engraving plate on gummed paper in the sheetlet format with line perforation 14 1 / 2, handwritten note to the printing ink and very early date of construction, here sample 7, small paper tears besides the plate edge nitration, very rare piece, decorative effect, expertized with certificate Ludin BPP