I am wondering if anyone can pls help me with a family tree project - I seem to have hit a hell of a brick wall!

Looking for any info on my grandfather's family:
->My grandfather was: Thomas Fraser (probably born around 1930, don't know where, suspect Ontario).
-> He had a brother whom I believe was named Ian (no idea on a date of birth for him).
-> Tom married a woman named Margaret Gurr (born 1931, Ontario). They had MANY kids together in Toronto, Ontario. Their marriage failed... he ended up with another woman named:
-> Louella Meawasige (she was a native woman, from Serpent River, Ontario, and she died Oct 31, 2012). Tom and Louella had several kids together as well, who all appear to have been raised in Northern Ontario.
-> I know the names of ALL of the kids he had with Margaret, as well as those he had with Louella -- I've traced most of them as far along as possible.

WHAT I NEED TO KNOW:
-> Anything about Tom's family! Where did they come from?
-> What were his parent's names? Where did they live?
-> Were there other kids besides Tom and Ian?

Tom and Ian are both dead - I never met either of them. My grandmother (Margaret) is dead. She rarely spoke of him. Louella is dead - died before I even knew about her. I haven't had luck reaching any of Louella's children (and don't think I should anyhow since I never even knew about them til recently)... and my own aunts and uncles are estranged from me and I cannot ask them. They never spoke of Tom either. :(

Any help, much appreciated.