Poortman 1F75

Marine Blue COB430f 1936-1938 Click for the Stamp Set

Black-blue COB430e ..1937 .

Cobalt Blue COB430d 1938-1939 .

Prussian Blue COB430c 1939-1940 .

Green-blue COB430b 1940-1941 .

Slate blue COB430 1941-1943 .

Pastel Blue COB430a ..1942 .

Used

1F75 Prussian Blue 1940 cancel