A ruling authority is needed for Guernsey banknote issues during the World War 2 German occupation of the island.
Perhaps ‘German Occupation’ as a ruling authority for this?
https://en.numista.com/catalogue/index.php?mode=avance&ct=banknote&se=World+War+2+issues&e=guernesey
The Germans allowed the islanders to issue small notes for denominations under £1 in response to a shortage of coinage. The note issues were balanced by the withdrawal of circulating Bank of England notes.
There was also a second, secret printing of notes by the islanders which were put into circulation immediately after liberation in 1945. I would place these under George VI as ruling authority.
