Source:
I have now made my great great grandfather, Robert Brewster, the brother of David Brewster's great grandfather, James Brewster of Ballintaggart. This makes him the brother of the James Brewster's brother, Charles Brewster, who emigrated to Philadelphia and then erected a gravestone to his father "Robert Brewster of Camus" in Camus Old graveyard. This meant I had a new great great great grandfather, Robert Brewster.
The original evidence for this was that David's father took him and his brothers to visit my Mary Brewster of Dromore. She told them that their grandfather, James Brewster (son of James brewster) of Ballintaggart had a brother called John and we concluded that this John was probably a full cousin of my great grandmother, Annie Brewster, and her brother, also a John Brewster. Ballintaggart and Domore are contiguous.
This was all speculation until David Brewster located a family tree he had drawn in 1973 based on information given to him by his father in that year. This tree was amazingly accurate in confirming details we already knew to be correct such as my great great grandmother being called Boyd and that she had four children. And it also showed that my John Brewster of Dromore was indeed a first cousin of David's John Brewster of Ballintaggart.
Even more surprisingly, it showed that Mary Brewster was not the illegitimate daughter of either Annie Brewster or Sarah Brewster but the daughter of a Thomas Brewster who was a brother of these two women. And it showed that he was married twice, with Mary seeming to be a daughter from the second marriage.
Found the birth of Mary where he was a "Puddler" living at 6 Martin's Land, Murrystown, married to Mary McMaster on 13th July 1866 in Glasgow.
Found his second marriage to Christina Galloway on 26 Dec 1871,
1881 Census:
Name: Thomas Brewster
Age: 38
Estimated Birth Year: abt 1843
Relationship: Head
Spouse's name : Christina Galloway
Gender: Male
Where born: Ireland
Registration number: 624
Registration district: Blantyre
Civil parish: Blantyre
County: Lanarkshire
Address: Aitkenheads Bdgs Blackleys Land
Occupation: Ostler
ED: 7
Household schedule number: 266
Line: 4
Roll: cssct1881_202
Household Members: Name Age
Thomas Brewster
38
Christina Galloway
29
Robert Brewster
8
Martha Brewster
6
Sarah Brewster
5
John Brewster
2
James Brewster
1
1891 Census:
Name: Thomas Brewster
Age: 49
Estimated Birth Year: abt 1842
Relationship: Head
Spouse's name : Christina G Brewster
Gender: Male
Where born: Ireland
Registration number: 647
Registration district: Hamilton
Civil parish: Hamilton
Town: Hamilton
County: Lanarkshire
Address: 6 Quarry Pl
Occupation: Coachman
ED: 14
Household schedule number: 34
Line: 8
Roll: CSSCT1891_310
Household Members: Name Age
Thomas Brewster
49
Christina G Brewster
39
Robert Brewster
18
Martha Brewster
16
Jannet Brewster
7
He must be dead by 1901 as Christina is living as Head of household with Robert, Janet G, William B and Elizabeth, aged 6.
I cannot find him in the 1871 Census, after Mary died and before he married Christina, to see if his daughter Mary was with him or if she had already been sent back to Ireland.
DB: The Registry office in Coatbridge on Mary's birth record sounded familiar to me. Alan reminded me of people my father knew from Scotland - Alex Mays from Coatbridge, and Lex Rankin. I never met them, but the names are familiar. Possibly they are descendants of Thomas, although Thomas may have gone there to work because he had extended family in Glasgow.