Hello Ellen,
We know that Donald Campbell in Reading from the 1881c is correct, we have the family forward from that in detail. My copy of the LDS data set shows his birth location as "Sunderland". However, if you look at the image page (mine comes from Ancestry.com) it shows "Sutherland". I thought this might have been an individual error, but when I look at people in Durness, some show Sunderland as well. Such as "George Brydon U 9 M Durness, Sunderland, Durham, England"! So, I've concluded that this was some sort of general machine translation error. Maybe it's just my data set?
Donald Campbell marries in 1875 and gives his father as Duncan Campbell, a shoemaker from Scotland deceased. Donald Campbell is in the 1871 census for Reading, lodging as a drapers assistant. So he must have come down pre 1871.
Looking at the IGI for Donald Campbells with a father Duncan from Sutherland, gives me only the one hit that I reported before. Do you see this IGI entry as well? All the IGI christenings give Durness as the location. Ann Campbell is christened on 12th Nov 1838, so she would be about thirteen in the 1851 census and probably still at home (or maybe in service?). Do you have access to the 1841 census? Would it be any good to us?
What is an OPR disk?
Cheers,
Phil