Hi Julie,
I am just going through the various documents I saved from the research into my grandfather.
I'm afraid I can't find my photocopy of the 25th Oct 1917 entry in the War Office Casualty Lists. This is the key entry as it links the KOYLI service number with his C.E.H. initials and Sunderland address. I will keep looking for it. If you ever go up to Newcastle, the Central Library may well hold copies of these lists.
I had more luck with the BEF Casualty List with his name on it, which I have saved electronically.
I have tried to attach it, but at 1.94mb it is too large for the max size below.
I am also happy to share some of the research on my grandfather. As your Grandfather was in the same draft covered by the research, it will hopefully explain how I was able to work out when he enlisted etc. The Pension Service Record of 36316 Fred Cowings survives which you can access on Ancestry. This illustrates the timeline. They were all conscripts mobilised just after their 18th birthdays from Newcastle, Durham and Sunderland.
I have lots of background info saved electronically on 7 / KOYLI, including the 7 / KOYLI war diary, trench maps and the personal diary of their Commanding Officer, Lt Col J T Janson who describes the incident on 26th Sept 1917 when your Grandfather was gassed.
I'm a bit stumped as to how best to get these over to you as they are rather large files. I have looked on the Great War Forum and the file limit is even smaller!
Regards
David