Hi, we corresponded about the Allans some years ago. I'm descended from James's uncle Robert Allan.
James was born at Craigton, Cairnie, 18-9-1843 and baptised 21-11-1843.
The 1851 census shows James with his mother and grandmother at Craigton. He is at school.
The 1861 census shows James at Budgate, Cawdor, Nairnshire, working as a cattleman for John Joss.
In 1868 he was working as a farm servant at Hillocks, Newhills, Aberdeenshire. On 4-12-1868 he married Margaret Ewen at Roadside of Garlogie, Skene. On the certificate he says his mother is still alive and gives his father as Alexander Allan, farm servant (Deceased).
The 1871 census shows the Allans living at 19 Lodge Walk, Aberdeen. James is a porter at a paper works. The only other member of the household is his wife Margaret.
Their daughter, Margaret Ewen, was born 13-4-1873. The family was living at 87 John Street, Aberdeen, and James was working as a railway stoker.
Their son, James, was born 17-4-1875. The family was living at 103 George Street, Aberdeen, and James was working as a labourer in a granite works.
The 1881 census shows the Allans at No. 26, 6 Black's Buildings, Aberdeen. The household consists of James, described as a stone turner (i.e. making granite rollers), Margaret, and their children, who are both at school.
The 1891 census shows the Allans at No. 4, 2 Black's Buildings. The household consists of James, described as a stone turner, Margaret, and their children - Margaret, a dressmaker, and James, an apprentice mechanic.
The Aberdeen Journal of 16-10-1899 reports on the results of a Board of Trade examination for engineers held in Dundee. "James Allan, 4 Black's Buildings, Aberdeen", passed first class. He is described as a candidate from the Dundee Marine Engineering Academy, Panmure Street, Dundee.
The 1901 census shows the Allans at 4 Black's Buildings. James is described as a stone turner. The only other member of the household is his wife Margaret.
The 1911 census shows the Allans at 4 Black's Buildings. James is described as a stone stone at a granite works. The other members of the household are his wife Margaret, his mother-in-law, Catherine Smith, and a grandson, Douglas T. R. Gordon, aged 9, who is at school. Douglas was born in New Jersey, USA.
The 1921 census shows the Allans at 4 Black's Buildings. James is described as a stone turner (he works for the Pittodrie Granite Turning Co., Ltd., Merkland Road). The rest of the household consists of his wife, Margaret, and a boarder, Annie Davidson, an unemployed woollen combination machinist from Harriot's in Rose Street.
Margaret Ewen died at 4 Black's Buildings on 28-4-1925. The death was registered by James, who described himself as a journeyman stone turner.
Thereafter I can find no definite trace of James.