Help please ww1 soldier

My grandad was initially in the Welsh Regiment 73148 and later in the Royal Welsh Fusiliers 80223 during WW1.
I would like to know exactly where he would have fought on the Western Front ( Victory and British War medals) and any details of his time in Ireland (Tralee) around 1918. He received a shrapnel wound to the shoulder and Mustard Gas poisoning.
As I live in Australia it is difficult to investigate and I only have the info from the War Medal Index.
Kind Regards
Ann Wilkinson:wacko: