I might be able to shed a little more light. My great-great grandmother was Mary Vivian, who was the daughter of John Vivian of Oakland, Ontario. She was the sister of Charles Vivian. Their mother was Sarah Tryphena Malcolm, daughter of John Malcolm and granddaughter of Finlay Malcolm who was the original settler of Oakland and founded a large clan in the area. Finlay Malcolm (1750-1829) was originally from Aberdeen, Scotland, settled in Penobscot, Maine, and joined the Loyalist forces during the American Revolutionary War. After the war hemoved to New Brunswick and then to Oakland Twp., Upper Canada, which is inland from Long Point on the north shore of Lake Erie, when it was being opened up in the late 1790s.
John Malcolm (1776-1846) was his eldest son and together with his brother Finlay founded a gristmill on his family's Oakland grant in 1806 and a sawmill in 1807. During the War of 1812 John was a Captain in the Oxford County Militia and the last land battle of the war was the Battle of Malcolm's Mills on November 7, 1814. It was more like a skirmish against a force of American regulars who had crossed over from Detroit, but the mill was burned, although later rebuilt. The mill had another moment of fame in 1837 when it was a rallying point for the rebels during the Mackenzie Rebellion. The Malcolms had been vigourously opposed to the Family Compact and several members of the family were arrested for participating in the rebellion, including John briefly. His brother Eliakim was charged with treason and was on his way to deportation in Australia when he was pardoned.
All this is to say that the mill had quite an early experience. I have the basic elements of the story from a pamphlet "Malcolm of Oakland Twp., Brant County, Upper Canada" compiled by R. Robert Mutrie as part of a series of Long Point Settlers Genealogies. I found it browsing on the internet. Eliakim is in the Dictionary of Canadian Biography and there are various sightings of Malcolms and the Mill in histories of the War of 1812 and the 1837 rebellion.
Mutrie says that John Vivian was the son of Stephen and Mary Vivian and was born in 1810. He moved in 1834 from Little Pethwick, Cornwall to Oakland and rented Malcolm's Mills in 1835, buying them in 1840 and operating them as Vivian's Mills until he died in 1870. Apparently there was both a saw and a grist mill. He and Sarah were married in 1836 and had three children, possibly more. Her dates were 1821-1862.