Oman 1977 Birds #2 10b (Penguin) set of 7 imperf progressive colour proofs comprising the 4 individual colours plus 2, 3 and all 4-colour composites unmounted mint
Oman 1977 Birds #2 10b (Penguin) set of 7 imperf progressive colour proofs comprising the 4 individual colours plus 2, 3 and all 4-colour composites unmounted mint