Hello Iain,
I have been researching on behalf of my partner who is a 3rd great grandson to Alexander Harrold & Janet Lawson. His paternal grandparents were 2nd cousins, their grandparents being Jessie & James Harrold, both children of Alexander & Janet.
From my research,the James Harrold/Mair/Moir who married Agnes Moodie Wilson was born 6 Feb 1873. James Harrold & Elizabeth Grigor were actually his grandparents. He most likely put their names on the marriage record since they pretty much brought him up. His mother was their daughter Mary Ann who had 8 illegitimate children, was somewhat mentally handicapped, according to the Poor Relief Records, and consistently refused help; - "she steadily refuses Poor House at all times and she might have received comfort and plenty by taking indoor relief. She is destitute beyond all the power of description and has been literally starving" This was from the Parochial Board of Elgin in 1889.
Michaele