I have inherited
a collection of stamps that dates back through my grandmother and great grandfather who both worked in post offices, with stamps dating back to +/- 1865. I have six albums of stamps from many countries that I have just begun cataloguing and it's going to be a long process for me
One of the stamps appears to be a Swedish Gustav V 20o Violet with '21' visible in the cancellation. From my brief reading it seems that the watermark (or lack thereof) determines whether or not the stamp has value. Am I correct in this assessment?
thanks in advance