One of the references on the index card was a book of memorials in the graveyard - I cannot now remember whether it was specifically for WW1 casualties or not. However, I it was a lucky find - as I had been searching for his father's grave for some time around the area where he lived, without success!!!
I am doing very little tomorrow, so I will dig out my records. I must have copied down [somewhere] exactly what the book was!!
However, whilst I was searching for the grave - I discovered that of another relative! My husband spotted it and I took a picture - never believing that it could be THE ONE!! When I checked at the archives, it was indeed the correct relative, his sons paid for the grave, and him, his wife and his daughter were all buried there!!