Somewhere I have a copy of The McCalmans singing THE DEATH OF MONTROSE. If it's of any use, The words as far as I know are as follows:

They brought him to the Watergate
A bound and helpless man,
As though they held a lion there
And no defenceless man.
They stood him high upon a cart.
The hangman rode below.
They drew his hands behind his back
And bared his noble brow.

CHORUS: Had I been there with sword in hand
And fifty Camerons by,
That day in high Dunedin's streets
You'd hear the slogan cried.
Not all the troops of trampling horse,
Nor might of mail and men,
Not all the rebels in the south,
Had born us backward then.

There stood the Whig west-country lords
At balcony and bower.
There sat the gaunt and withered dames,
Their daughters all around,
At every open window
Asking who this fool might be.
Those black cold covenanting carls
This goodly sport to see.

He is coming. He is coming
Like a bridegroom from his room.
Comes the hero from his prison
To the scaffold and his doom.
There was glory on his forehead.
There was lustre in his eye,
And he never went to battle
More proudly than to die.

Sorry I can't provide a tune, it's all in my head. K.