UNITED NATIONS (1976) Conference on Human Settlements*. Set of 12 imperforate progressive proofs. Scott No 277, Yvert No 268. From the UN printer archives. Rare!
AVAILABLE AT $100
SENEGAL (1980) Planting trees*. Set of 9 progressive proofs including final colors. Scott No 530.
AVAILABLE AT $50
MAURITANIA (1985) Grain harvest*. Set of 3 progressive proofs including final colors. Fight against desert encroachment. Scott No 589.
AVAILABLE AT $25
MAURITANIA (1985) Planting brush*. Set of 3 progressive proofs including final colors. Fight against desert encroachment. Scott No 591.
AVAILABLE AT $25