Here's harry's version as recorded by Leslie Shepard.

MAIDS OF AUSTRALIA

As I walked out by the Oxborough banks
Where the maids of Australia do play their wild pranks
Underneath a green shady bower I sat myself down
Where the birds sang so gaily enchanted all round
In the native, the plains of Australia
In the forest, the native Australia
Where the maidens are handsome and gay.

[I sat on the bank there for hours two or three,
A fair damsel came out from behind a green tree
To cover her body it was her intent
She slipped past the bushes made straight for the bank
In the native, the plains of Australia
In the native, the plains of Australia
Where etc.]

Now she dived in the water without fear or dread
Her beautiful limbs she exceedingly spread
Her hair hung in wrinkles, her colour was black
Sir, she said, you will see how I float on my back
In the stream of the native Australia
On the stream in my native etc.

Now being exhausted she swam to the brink
Assistance, kind sir, or I surely will sink
As quick as the lightning I took hold of her hand
My foot slipped and we fell on the sand
In the native, the plains of Australia etc.

We frolicked together in the highest of glee
In the finest Australia you ever did see
The sun it went down and the clouds did resign
And I left this fair maid of Australia
I left this fair maid of Australia
Then I left the fair maid of Australia
Just when the sun went down.

[Now six months being over and nine coming on
This pretty fair damsel brought forth a fine son
Oh where was his father? He could not be found
And she cursed the hour that she lay on the ground
In the native the plains of Australia
In her native the palins of Australia
Where....]

This last verse in a similar form is found in American versions but not on any other British versions.

I'll leave it there for now for comments, preferably to how this might have come about.