I realise I've come late to the party, but I wonder if you are able to find anything on George/Robert ROY.
This is taken from the Morayshire Roll of Honour
"ROY, Robert George. No 17910, Sgt., 2nd Seaforths; born at Parish of Drainie, 15 Sept 1880; Joined at Glasgow, 4th August 1914.; served in France and Salonica; six times wounded; awarded M.M. Son of George Roy, 259b High St, Elgin. Occupation; dock labourer."
but I can find no further military information. His parents were George ROY & Mary GORDON, married November 27 1886.
I see you are interested in the K Class submarines, my grandfather's brother, James McLennan, was a stoker on the K3. Having read the "K Boats: Steam-Powered Submarines in World War I" by Don Everitt I think he could be excused just about everything.