CHAD (1972) Stylized heart*. Trial color proofs in strip of 5 with multicolor. World Heart Day. Scott No 251, Yvert No 244.
AVAILABLE AT $75
NIGER (1972) Surgeons*. Heart-shaped globe*. Trial color proofs in margin strip of 5. World Health Day. Scott No C182, Yvert No PA182. Hard to find!
AVAILABLE AT $100
MALI (1968) Intertwined hearts*. Trial color proof strip of 5 with multicolor. Sister cities. Scott No 107, Yvert No 109.
AVAILABLE AT $60