I'm afraid I've only just noticed Jim's post. Thanks for that.

It's odd that Marjorie Kennedy Fraser would have bothered to "translate":

I dal a du vil
I dal a du ho ro

as:

Eetl a doo veel
Eetl a doo ho ro

Why translate real Gaelic (albeit just mouth music words) into faux Gaelic ones? Maybe she never saw the words written down and she wrote down what she thought she heard? Anyway, I always sing "I dal a du vil."

Many thanks for supplying the Gaelic song title - with the aid of which I've now found some lovely recordings of the original Gaelic song: one by an anonymous community group, here; one by Julie Feeney singing with an Irish duo Size2Shoes, here; and one by Julie Feeney singing solo, here.