That looks very possible Colin.
Andrew also christens a JAMES 1 Apr 1759
Looking at James his wife seems to be a Isabella HALL
James is on 1841 Census age 80
Buried
Sibbaldbie Old Churchyard
Burial or Cremation Place Applegarth Town, Dumfries and Galloway
Death Date 2 Dec. 1844 age 83/84
Spouse Isabella Hall Cowan Death May 1825 age 65/66
In memory of Isabella Hall, spouse of James Cowan, tennant in Gall, who died 11th May 1825 aged 66 years. Also the said James Cowan who died 2 December 1844 aged 84.
Just found it a coincidence as siblings often married siblings.
So possible???