They are classed as Cinderella stamps.
From Lundy, an island off Great Britain somewhere (not too knowledgeable about it) Change title to include the word Lundy and you will get the people who know the most.
Wikipedia:
http://en.wikipedia.org/wiki/LundyEric Blood-axe was a real Viking, well known to people of Great Britain.
Wikipedia article:
http://en.wikipedia.org/wiki/Eric_BloodaxeI hadn't heard of him except early in the day I ran across someone called the same name on
ebay selling stamps! I thought at the time that it was rather a blood thirsty name to call yourself if you wanted people to send you their money.