Bernard Hodgson, of Crawley, West Sussex, whose father Herbert picked up the bible, used the internet to track the only clue - the service number inscribed across the top outer edges of its pages.
The original owner was Private Richard Cook, from Colac Bay, in Southland, who fought with the Otago Regiment of the New Zealand Expeditionary Force and died during the battle of Passchendaele in 1917.
Now, Mr Hodgson hopes to make contact with members of Pte Cook's family and connect the final pieces of the puzzle.
Herbert Hodgson was in the Royal Irish Fusiliers and died in 1974.
In his memoirs, being published by his family later this year, he recalls falling into a shell hole by accident during an attack on the German lines in 1918.
He grasped a book in the mud, "shoved it in his pocket" and was knocked unconscious when a shell exploded nearby.
Recovering in hospital he still had the book with him.
"I was sent back to a field hospital and there I told an officer about my find and asked what I should do with it.
"He told me that in the chaos going on it was pointless trying to find its rightful owner. `I'd keep it if I were you,' he said. `It might bring you luck'.
"It occurred to me that having come through unscathed after being blown up by a shell it might already have done just that," Mr Hodgson sen said.
His son's research revealed Richard Cook was the son of Reuben and Mary Jane Cook, of Colac Bay.
He died aged 26 on October 8, 1917 and was buried in Etaples Military Cemetery, in France.
Mr Hodgson would be delighted to hear from any of Richard Cook's family.
Riverton historian Catherine Hill told the Otago Daily Times she had considerable information about the Cooks which was sent to the Wallace Early Settlers Association in 2006 by Aucklander Earl Cook, a great nephew of Richard Cook.
Reuben and Mary Jane Cook emigrated from Wales in the 19th century and spent many years at Rimu, on the eastern side of Invercargill, before shifting to Colac Bay where they lived for more than 30 years, she said.
Richard was one of 13 children and the youngest son.
Only four of the children were still alive in the 1920s, the rest having died as infants, in war, or in accidents.
Richard was not married and had no children, Mrs Hill said.
She had been unable to discover any Cook relatives still living in Southland.
Anyone can send information about Pte Cook to: allison.rudd@odt.co.nz or
