Like yourself and I'm sure many others, I have had a good look for possible births and the existence of the people he names as parents. All without success.
There were 3 children of the union between Mabel and G.J.
Of course you will not name them here, but may I ask if the choice of names reflects others in the DHUE family? Were they DHUE family names?
Or is it possible they were names connected to G J's side?
It is really clutching at straws to use such clues in your research, but it may be worth consideration at this point.
Sue