Welcome to the Forum Paul.
I'm not sure how much you know about the Bradford Pals Battalions, or the battle of the Somme where both pals battalions from Bradford took such heavy casualties, including your great uncle. There are two books on the Pals. One by Ralph Hudson is currently out of print, but I think you should be able to download it here
http://www.bradlibs.com/bradfordpals/index.htm The other is more recent and still in print, by David Raw.
The Long Long Trail, will give you an idea of the history and formations involved.
I pay a few visits a year to the reference library in Bradford, and can check the local index "All our Heroes" in a couple of weeks for any mentions. Once you have made 10 posts you can send personal messages, so feel free to contact me direct. There are other members on the forum much more knowledgeable on the West Yorkshire Regiment, and some of them will probably be along soon.
Keith