Nice coins there, Siberian Man! Note the H mint mark on the Guernesey. Also that is the old type with 3 "E"s in the word.
There is probably an explanation for that odd denomination of the money of Guernesey. Perhaps you could enlighten us?
Double comes from the French double tournois (liard) which circulated (amongst other things) on the island prior to the introduction of the Guernsey coins. "Guernesey" is the French spelling.