If my research is correct, the James McGruther you are looking for is James Duncan McGruther, the oldest (I think) child of George McGruther and Jane Laurie/Lowrie, born in born on the family homestead, N1/2 Lot 17, Concession IV, Innisfil Township, in what was then the Home District of Upper Canada, later Simcoe County, Ontario.
George emigrated from Ireland at sometime prior to 1833, the first documented year of residence in Innisfil.I have been able to find little personal information about him; his age, place of origin in Ireland, parents, siblings, etc., exact date of death and place of burial are all unknown...still looking, but so far no luck.
Jane Laurie was the daughter of John Laurie and Mary ?John was a weaver from Scotland given passage to Canada in 1820 through a Scottish Settlement Society with a number of other families.Their original land in Lanark County was so poor they move to Innisfil c.1831.
George and Jane have (at least) eight children, 4 boys, 4 girls.James marries Jennet Fountain/Fontaine c.1857; she is a daughter of Louis Henri Fountain/Fontaine and Marie Joseph Boudreau, both originally from Quebec.Jennet is also, interestingly, the maternal aunt of James' brother William's wives Mary and Rosanna Young, making him his brother's uncle by marriage...
If you're interested I have more information about the family.