I stumbled across the following entry on your site: "Duckenfield, John. King's Royal Rifle Corps 2nd Bn. Rifleman. Service No. 2141. Le Touret Memorial, Pas de Calais, France. 10-Mar 1915. John was approx. 17 years old when he was killed. Son of Harry and Hannah Duckenfield. They lived at 12 Marsden Lane, off Edward Street, Sheffield. Le Touret Memorial lists the names of over 13,000 men who fell in the area before 25 September 1915 and have no known grave. John was reported missing since the 10th March 1915 in the Sheffield Independent newspaper."
I am quite confused by this. My Father-In-Law is the son of John Duckenfield, who was the son of Harry and Hannah Duckenfield, as above. I can assure you that he did not serve in WW1,and my Father-In-Law witnessed his father's death when he was trampled to death by his own horse on Kelham Island at the age of 49. John was the father of 6 children. I would be interested in discussing the documentation that led you to the conclusion that this was the John Duckenfield that served, and died, in WW1.
If it is of any help, I have extracted all the birth, marriage and death records for the Duckenfield (et var) surname from 1837 to 1950.