Many thanks for the replies. Plenty of food for thought.
The soldier is James Finlay and according to the 1861 Census in Scotland, was born c1785 Donegal, Ireland. I'm not even sure that this soldier is the same person, but need to start somewhere.
The info has been supplied by a cousin (which means this is all foreign to me...pardon the pun) who believes that JF was born c1785 Donegal and he married a Sarah Hunter around 1813/14 in Donegal. I did find a reference to his enlistment in 1804, which I'm trying to find again, but I think it gave him as born in Donegal.
At the moment, I'm just trying to solve this Tuam puzzler.
Thanks, Eric