Mckenzie's immigrated to Canada

Some of my Mckenzie ancestors immigrated to Canada in the 1850's. John Mckenzie was a farmer near Dalbeattie Scotland. He farmed a 200 acre farm called Auchenninnes. The lease on the farm ended in 1856. The family of 11 are recorded in the 1851 census in the parish of Urr. In the 1861 census the family is no longer recorded. Robert and Grace, two of their children, are found in later census years, but the others I have wondered about for over twenty years. Many years ago someone submitted three of the missing to the pedigree resource file; William, Agnes, and Anne. They used the abbreviation for Scotland as 'SCT'. Since the search engine did not recognize 'SCT' as Scotland they remained missing until now. I made the connection on newfamilysearch that connects people by relationships. I have been looking for direct evidence that connects the three to my line. Ancestry.com has indexed the Canadian census records and many vital records, so I was able to search for them quite easily. I found William, the oldest, in the 1901 Ontario census. The 1901 census records a birth date and it is the same as that recorded in the parish registers in the Parish of Urr, Feb 9 1830. The evidence does connect them to my Mckenzie family in Urr parish, Scotland. Agnes married 14 Nov 1861 at the age of 18 to Alexander Gibson in the St. John's, Queen's Road Presbyterian Church in Newfoundland. Their are no Newfoundland records on Ancestry.com.
The remaining three children, John, James, and David Mckenzie, I image would have settled in Canada somewhere. John was born 4 Dec 1833; James was born 26 Oct 1835; and David in 1846. If they lived to 1901 I may be able to identify them in the 1901 census. I think their descendants are going to have to find my website, as their are to many to search.