I thought you might like to know that there is an estate file for a John O. Magnusson at familysearch.org He died Sept. 12, 1912 atWynyard.
It is 31 pages, many of them with not much info on them, but page 25 shows Magnus O. Magnuson and Ole O. Magnuson, farmers of Wynyard and Margaret O Magnuson, also of Wynyard, widow. Margaret is mentioned earlier as being mother of John - the deceased.
familysearch.org is a free site so you can look at the estate file for free
I also did some googling for a book by Ole of Olafur and found the title.
It is shown as Author:Olafur O. Magnusson Title:Landnam Islendinga sunnan Quill vatnanna Saskatchewan, Almanak (1950)