Barbuda 1981 Marie Curie 90c imperf progressive colour proof printed in black only (as SG 547) unmounted mint
Barbuda 1981 Marie Curie 90c imperf progressive colour proof printed in black only (as SG 547) unmounted mint
Barbuda 1981 Marie Curie 90c imperf progressive colour proof printed in black only (as SG 547) unmounted mint