The Marine City Duddy's are descended from my father's (Thomas Samuel Green, 1914-1992) grandparents. His mother, Mary Ethel Duddy Green (1889-1988)was the eldest of (I think) 5 children, including George and Thomas (and Sadie married Robert Kinyon and Effie? married Watson.
My grandmother was instrumental in helping a researcher with a book documenting the Mills family (her mother's family) and it contains a lot of detail on the Duddy's - including the names I can't think of right this minute above.
I'd be happy to dig out the book and give you more information if you're still following this forum.