Malcolm, the version I heard is almost the same as yours with the following small amendments.

AR FA DE LA LOW

There's a lilt in this song I sing, there's laughter and love
There's a tang of the sea and blue from heaven above
Of reason there's none, and why should there be forbye
As long as there's fire in the blood and toe and a light in the eye

Ar fal de la low ho row ere fal de la lay
Ar fal de la low ho row ere fal de la lay
Ar fal de la low ho row ere fal de la lay hey
Fal de fal do ho ro aire fal de la lay

The heather's ablaze with bloom, and myrtle the sea
There's a song in the air, the road a song at our feet
So step we along as light as a bird on the wing
And as we are stepping we'll join our voices and sing
CHORUS

And whether the blood be highland, lowland or no
and whether the skin be white or black as the slough
Of kith and of kin we are one be it right be it wrong
As long as our voices join the chorus of song
CHORUS


BTW, Seamus Kennedy does a great job on his "Favourites" CD.