I have had another dig into this today. I started with what I think is a red herring in an article on a Hugh (1802-1876) who was deported to Australia in 1840 for stealing a sheep and then have his wife help him to try to escape from prison. He was a shoemaker but was from Achahorn so, although interesting, geographically it seems unlikely. The below trial papers also relate to a Hugh who was a "journeyman shoemaker" (which may be the same person):
High Court of Justiciary Trial Papers
Title Trial papers relating to Hugh McGregor
Name Hugh McGregor
Role Accused
Crime Theft by housebreaking, and prison-breaking
Trial Date 24 April 1839
Trial Location Perth
Verdict Guilty
Verdict Comments Guilty in terms of own confession - theft by housebreaking.
Sentence Transportation - 7 years
NRS Reference JC26/1839/27
Notes The Advocate Depute passed from the remaining charges.
The 1861 census for Monkswearmouth (Sunderland) shows Duncan's birthplace as what reads like "Barnparish Scotland". It has been suggested that this may be Barony which seems possible.
There is a Hugh McGregor born in Barony on 1 May 1803. His parents were John and Christina nee Kirk.
There is a marriage between Hugh McG and Isobel Cunningham at Barony in August 1818. If this is the same Hugh he would only have been 15, but Scottish law may have allowed that at that time.
Hugh and Isobel then went on to have children, Isobel (1819), Alexander (1821), possibly Agnes (1823) and Hugh (1824). I still can't see the birth of Duncan recorded which would have been 10 years later, but still possible. I'm not at all sure if I'm going down the right track here so am interested in how the others who are interested are fairing.