Thanks to a Dutchman I discovered a review of 2018 book: 'Heligoland: Britain, Germany, and the struggle for the North Sea' by Jan Ruger. One passage is cited: See: Book review: ‘Heligoland’ by Jan Rüger Note there is a link to non-Amazon orders Republished in 2018 as a paperback and a lot of complimentary reviews on: https://www.amazon.co.uk/Heligoland-Britain-Germany-Struggle-North/dp/0199672474/ref=sr_1_1?_encoding=UTF8&camp=1634&creative=19450&keywords=jan+rüger+heligoland&linkCode=ur2&qid=1642072234&sr=8-1&x=0&y=0 There are a large number of threads elsewhere on this website, most refer to the 'Big Bang' and the surrender in 1945.
