Worth harvesting, I'd say, if we can get a tune.  Dylan apparantly recorded a similar set, but so far as I know acknowledged no source.

Polly's Love is also known as The Cruel Ship's Carpenter, The Gosport Tragedy, and so on.

In the Forum:

Polly's Love (Waterson-Carthy)  Two texts are given; Polly's Love, transcribed from a Watersons record; they learnt it from Jim Eldon, who got it from an unspecified singer in the West Riding of Yorkshire; and The Dreadful Ghost, from a record by Barrand and Roberts.  No traditional source is mentioned in the thread for the latter , but the sleevenotes of the record state that it is a Canadian set, "collected by Helen Creighton in the Maritimes, collated with Peacock's Newfoundland texts".  Also some useful information from Bruce Olson.  Steve Roud assigns both songs the same index number, but the two branches have grown apart over the years, and are often considered separately.

In the DT:

THE CRUEL SHIP'S CARPENTER  With tune; "from the singing of Mike Waterson"; no traditional source named.
PRETTY POLLY (2)  With tune; American set from Dock Boggs.
THE SHIP'S CARPENTER  With tune; from the Penguin Book of Canada Folk Songs, Fowke. Noted from Leo Spencer, 1962.

There are two entries at  The Traditional Ballad Index

Cruel Ship's Carpenter, The (The Gosport Tragedy; Pretty Polly)  [Laws P36A/B]
Pretty Polly (II)  [cf. Laws P36]

Examples, with audio files, at  The Max Hunter Folk Song Collection:

Pretty Polly Come Go Along With Me  As sung by Ollie Gilbert, Mountain View, Arkansas on June 25, 1969.

Molly Girl  As sung by Mrs. Ed Newton, Gainesville, Missouri on June 10, 1958.

Pretty Polly  As sung by Harrison Burnett, Fayetteville, Arkansas on August 18, 1960.

Pretty Polly  As sung by Sara Jo Bell, Harrison, Arkansas on August 25, 1969.

Broadside editions at  Bodleian Library Broadside Ballads:

The Gosport tragedy: or, The perjured ship-carpenter  To the tune of: Peggy's gone over the sea. Printed and Sold at the Printing Office in Stonecutter Street, Fleet Market; no date.

The Gosport tragedy; or, the Perjured ship carpenter  Printed between 1797 and 1846 by J. Turner, High Street, Coventry.

There are a number of editions from various printers of Polly's Love; here is one:

Polly's love, or, the cruel ship carpenter  Printed between 1819 and 1844 by J. Pitts, Toy & Marble Warehouse 6, Great St. Andrew Street, Seven Dials (London).

These are large images.