CB,
Kingskerswell is correct, the Presbyterian registers list those that served, including dead and survived.
So William on the Ebrington Church memorial is the correct one.
The main differance with the Presbyterian church rolls as opposed to the City War Memorial list is that the church took the names of its members at the time of the war [as well as could be remembered as some families had moved on by the time the lists were compiled], hence the Adairs being on Ebrington's list, whereas the main Londonderry war memorial committee only allowed people who were born or had lived in the City for a large number of years.
Aghadowey, i do not believe there is conflicting information, just a mistaken detail being repeated.
John was a member of the 11th Btn [Donegal & Fermanagh Volunteers] Royal Inniskilling Fusiliers, 109th Brigade, 36th division and was killed in the attack on the 1st July 1916 when the Division gained its famous reputation.
This was from Thiepval Wood, the Somme, France.
John was not a regular soldier, he was a 1914 volunteer. you can tell this from his service number and the date he landed in France with the Ulster Division.
He enlisted in Belfast and appears to have been born in Omagh.
Rob