Thank you so much for your responses and links.
The name of my friend's father is John Wisniewski, born in Poland in 1914. Looking at the links I see a John Wisniewski who died in 1996, but my friend is pretty sure he was still alive about 4 years ago. His last address was Oshawa, 14 Grandview St. North. Today his daughter Christine Majanew seems to live there. It may be possible that John is still alive and lives in a nursery home.
I'll post another query telling his name.