The only major change I could find would be is to change this line:

And my hair thin falls watching Cowan's braw
And by the Union Jack

to

And my hair thin falls watching callants braw
Stand by a Union Jack

'Callant Braw' is a Scots term often found in music and literature to describe a fine, young man.

Changing 'and' to 'stand' makes sense of the lines. As I listened to the song several times Alistair could be singing either word.

Thanks again, Mudcatters.

Catriona