Hi Val,
I'm sorry I've taken so long to reply to this, I make email accounts, then I forget to check them.
1)I took a look at that link, and I don't know where the site owner got the date of birth (likely 1901 census), but without actual proof, I can't say it's accurate. Murdoch's older sister, Catherine (she married Angus McCALLUM, and is well established through all the census images as being older than Murdoch) gives her year of birth as 1839. According to the rest of the census info, Murdoch was born anywhere between 1839 and 1841.
2)I have seen the burial year for Murdoch before. I have gone through the Manitoba death registration site with every combination and I can't find a death registration. Someone told me that the headstone says 1910, but mistakes can be made on them - especially if the stone was not erected immediately: maybe children get together later and pay for a stone, and the information is mis-remembered. I have two stones in my family with incorrect dates on them.
3) I have never seen ANYTHING which gave the birth surname of Murdoch's mother, Mary. I know she died out in Manitoba, but I haven't seen where she is buried either. My cousin told me that Mary was shipped back to Kincardine to be buried, but I have never seen proof of that, so I am not going to count it as true until I DO see proof. I don't know where the person who made the site got their information from, so I can't check the source there.
4) I can tell you a little more of Murdoch's history, and his family. Email me at maermaid at gmail dot com. I descend from Murdoch's brother, Angus Edward.