I have this one - Herring Boat

Issued for the "Freedom from Hunger" campaign of the U.N. Food and Agriculture Organization - Mar. 21 1963
Scott's #355 A80 7.50k multicolored
25 25 <----- what this numbers mean?
Greetz,
Bob
P.S.: The colors on the picture look faded, on the original stamp are quite crisp and fixed