Lawrence & Cohen 2 Cent Stamp: RU10aDie Approved May 2nd 1865First Issued July 1865Last Issued July 4th, 1866Material is Old Paper1,149,750 Issued This 4 cent variant was designed, but never issued. RU11a, Old Paper RU11b, Experimental Silk Paper RU11c, Silk Paper 5 Cent Stamp: RU11a, RU11b, RU11c Die Approved May 2nd, 1865 First Issued July 1865 Last Issued March 1874 Materials: Old Paper, Experimental Silk Paper, Silk Paper 5,500,408 Old Paper Issued 2,616,192 Silk Paper Issued Toppan, George L., et al. An Historical Reference List of the Revenue Stamps of the United States: Including the Private Die Proprietary Stamps. Castenholz, 1990. SCARLETT, Oscar. A Complete Cyclopædia of All the United States Revenue Stamps: Including Document, Match, Medicine ... and Other Tax or Revenue Stamps. William E. Scarlett, 1893.