I have been trying to find the words to this song, and I have transcribed what I can make out (with a few gaps) from an old recording of the McNulty family.

DOWN BY THE RIVER MOY
        
Thy banks so green, thy waters clear and thy bed a golden hue
The valley of thy pathway is a glorious thing to view
Thy whirling eddying waters wild go dancing forth with joy
Which fills my soul with thoughts of you o beauteous river Moy

How oft I trod those banks so green on either side the stream
With boyish glee and down the lee while birdsong __________(?)
That echoed from the hills around ________________________
Oh those happy happy boyhood days down by the river Moy

Then search Great Britain o'er and o'er and dear old Ireland too
A fairer land you could not find that seems so fair to view
When evening falls on all the scene and the moon shields ______
____________________________________________________

Three thousand miles divide us now, Columbia is my home
No time nor space can e'er replace the love that's sure to come
Whene'er my thoughts revert to thee once more I am a boy
Sporting with my playmates dear down by the river Moy

But oft its long ago since then for fifty years have fled
My dark brown locks are frosted now and my youthful days are spent
But hope __________________it will be my greatest joy
The day when I will once more see my own dear river Moy

- If anyone can fill in the gaps that would be great! (Or correct my mistakes!)
Cheers,
Quokka