CSA Catalog #U-1b, the 1955 2¢ Altered Plate, Dietz 1955 sheets of 100 with inscription “Commemorating the 69th Annual Convention of the American Philatelic Society, Norfolk, Virginia, September 21, 22, 23 & 24, 1955.” Left edge does not fit on the scanner bed as is too large, but it is all there and sound. A sheet of 100 catalogs $50 in the CSA Catalog.