Hi my grandfathers brother John Frail died on the same day as your uncle 9th May 1915, i found his name when i went up to Scotland two years ago and i found him there, i am certain if you look at the website
www.cwgc.org. you will see where is buried and i am quite sure if he is there he will be on the memorial in Dunfermline, its in the old Abbey and i was quite surprised to see my grandads brother there so ave a look at that website, John Frail was in the same regiment as your uncle
Lukie