PROOFS AND IMPERFORATE STAMPS UNIT: 1950's-70s, representing material of 18 different countries, including about 100 imperforate stamps or trial color proofs, 50 epreuves de luxe, many complete sets, most powerful are French West Africa, Central African Republic, Gabon, Mauritania, Republic Upper Volta and Senegal, some duplication, overall nice condition (we found a hint of toning on two sheets), full OG or no gum as produced, NH, VF, Est. $500-$600 (Image)