Oman 1974 Napoleon 2b (N at Island of Lobau) set of 5 imperf progressive colour proofs comprising 3 individual colours (red, blue & yellow) plus 3 and all 4-colour composites unmounted mint
Oman 1974 Napoleon 2b (N at Island of Lobau) set of 5 imperf progressive colour proofs comprising 3 individual colours (red, blue & yellow) plus 3 and all 4-colour composites unmounted mint