If it's any help at all, I have a Victorian Valleys ballad with the Mochyn Du verses in Wenglish:

The Mochyn Du

All you people, come and listen
Teardrops in your eyes will glisten
Pain will now your heart be rending
At your Mochyn's sudden ending

CHORUS: Oh how sad indeed are we
Oh how sad indeed are we
There was grief and tribulation
When we lost the Mochyn Du

What did cause the termination
Of our Mochyn's pilgrimation?
Was it too much wash or barley
That did waft her home so early?

Yes, the truth we must be telling
Too much grain her stomach swelling
She got very ill and poorly
Closed her eyes and went to glory!

Quickly Dai ran to Llwyncelyn
Fetching Matty to the Mochyn
Matty said, to our great horror
That the pig could not recover!

Then we built a silver coffin
Silver knobs and velvet trimming
And a vault with bricks and mortar
In the churchyard we did order

Then we sent to Isaac Thomas
For his hearse, which is so famous
And for horses black as mourning
For to drive our poor old Mochyn

Then the Reverend Thomas Griffiths
Came to read the funeral service
All the people there were sobbing
At the funeral of the Mochyn

Mary Jones and Peggy Williams
Led the way in solemn silence
All the people in the county
At the grave were weeping plenty

Then we went home, nice and tidy
Each one's heart was very heavy
But the girls were crying shocking
'Cause they'd gone and lost the Mochyn!

Mick Tems