Thank you, bbart, for the reply. As aghadowey said, I had posted this previoulsy and then saw this forum topic. These are my first posts, so still learning.

That's very kind you looked up the censuses. It's good to hear there are many other examples of duplications, and I do think this is the same person.
Thank you for the link to the Portage newspaper, I have not seen that notice. I will be checking out the UofM site.
I have hit a deadend with Duncan, and answering this question is helpful. The earliest I can confirm is his marriage in 1848 and then recorded in an 1851 Ontario census, inlcuding his wife and son. Earlier Canada census only list head of household and he may still be living with parent(s). He is reported to be born in Argyll and its been problematic trying to find his parents. I have ordered a death record for both Duncan and his wife that might provide this info.