No unfortunately I have not been able to establish Robert's parentage as yet. I have not been able to find a christening for him in the right time frame in the OPRI. His grave though is near other Moffat family graves in the Moffat cemetery.
I am not surprised to hear that he has descendants in Canada. Apparenttly his widow died in "Canada West" in 1867. Do you have a precise death date and place for her?
Quite a few years ago I found references to a Herbert Renwick, who I think must have been a brother of Jean's, in Canada prior to that time.
Robert was my 4x great-granfather. I am descended from his daugter Ann.