Yes, Cyril sang that one too. He sang three verses to start it which are explanatory.

First verse as above. 'A farmer he lived in the West Country...'

then
A fine young man came a courting them, (hey down etc.)
The oldest one got stuck on him. (and I'll be true..)

He gave the youngest a beaver hat
The oldest one got mad at that

O sister, sister, lets walk the seashore
And watch the waves as they roll o'er

Then the river's brim verse. The rest was pretty much word-for-word as above. Don't know who added the verses, but they do give a motive to the sister, if not the miller.