Thank you both for your replies.
Monica, the reason I thought this may be the right Robert Cameron is that the information regarding his working for the farmer John Grant at Pitgaveny came from a "Register of Corrected Entries" attached to the birth certificate of his son (another) Robert Cameron born 11 Feb 1857, illegitimate. Mother is one Jessie Harrold, born Dallas abt 1834.
I had previously found Jessie in the 1861 Census, at Easter Calcot's Bothy, St Andrews Lhanbryd, and when I purchased the actual census image yesterday from ScotlandsPeople I realised that she was working in the next door household to the farmer John Grant.
It does seem like too much of a coincidence and I thought perhaps Robert may have been "Gow" because it was his mother's surname......Jane ?? A bit of a stretch, I know, but possible.
Plus, the usual residence given on 1865 death certificate is given as Calcots, St Andrews Lhanbryd. However, this is just a Census, so proves nothing one way or the other.
Obviously though the birthplace of Rosskeen is a giant spanner in my theory, lol!!