I got in touch with Vin Garbutt's Home Roots Music. Vin himself provided these lyrics, and he applauded @scouse for his transcription. Pretty close!

THE LEGEND OF ROSEBERRY

The harvest moon was waning o'er Arncliff's rich domain.
The silver stars shone sweetly on the rock and the wooded plain,
When from her stately palace, Northumbria's princess trode.
To question that famed auger in Arncliffe who abode.
Oh,wise and dreadful wizard a godlike gift is thine.
What speaks the heavenly prophet of Northumbria's son and mine?
"The morrow shall thy darling in deaths embraces lay"
So speaks the heavenly prophet, tis midnight, now away.

Back to her stately palace with cavalcade she rode.
This night at least my darling, I'll trust thee to thy God,
Osmotherly and Ingleby, Swainby and Stokesley town,
Much marvelled, greatly wondered, to view that route come down.
Below that oak tree forest of Osnaburg's huge hill.
The proud procession halted, the cavalcade stood still.
With toilsome weary marching, she reached the towering height,
Rejoiced at, free from danger, she bore her cherub bright.

And then, a lovely vision, lay stretched beneath her feet.
The groves of sweet Upleatham, the shores of the Cargo Fleet.
Yet wouldn't that Lady shudder to view the boundless sea,
Even silver Tees brought terror, so lovely though it be.
And now like marble statue in holy sleep she lies
And by her like an angel, the royal orphan smiles
But then a lovely vision beneath that mountain brow.
A fountain fair enchanting with heavens own colours true.

Within that crystal mirror he views a lovely form.
With equal love enticing him into its watery home.
Oh fate, oh dread, he clasps it, one cry and all is o'er.
The treacherous spring enfolds him. Prince Oswy is no more.
And on that rocky precipice, beneath that wooden knoll,
A hermitage the Lady reared, with Mass's for his soul
And with that holy hermit, full oft devoutly prays,
What God has given God takes away and vindicates his ways.