I learned the Peter, Paul and Mary version in the middle 60's when I was a regular at 'Folk Union One' , run by The Watersons at the 'Bluebell' in Hull. After performing it one sunday evening, Norma Waterson gave me this extra verse, which I still sing.

All the maids of this country will all be very glad
When they hear the sad, sad story, my Polly Von is dead.
You can take them in their hundreds and put them in a row,
Polly Von, she'd shine above them like a mountain of snow.

Maybe this is the verse Naemanson is thinking of. A great last verse, which I still sing.

By the way, I have never come across a bad version of 'Molly Ban', 'Molly Bawn', 'Polly Von' or 'The Fowler' or whatever else it's called. Johnny Jones of the Oyster Band used to do a great version.