My research so far has taken me back to a number of farm estates around Glamis Castle. My ggg grandfather, Christopher Rattray, was apparently a gardener at the Castle. He was born in 1820 to Thomas Rattray and Elizabeth Arnott at Warren Farm. (Thomas was born around 1791 in the parish of Glamis). Christopher married Jane (Jean) Tough and they had 6 children including my gg grandfather William, also a Glamis Castle gardener, I believe. These children were all born at Ballindarg, between Glamis and Kirriemuir.
I can find no information prior to the 1791 date (even the clan database draws a blank), so if anyone knows anything of interest I'd love to hear from you.