The Bodleian copy, Douce Ballads 1(72a), S. Bates, London (Giltspur street) is dated by them as ca. 1720. It is identical with the Ballad 74A, Fair Margaret and Sweet William, in Child. In the Bodleian Collection, the title on the broadside is "Fair Margaret's Misfortune, Sweet William's Frightful Dreams on his Wedding Night: With the sudden Death and Burial of thise Noble Lovers. To an Excellent New Tune (inserted in ink, not readable by me)." Easily seen at the Univ. Hawai'i website or in vol. 2 of the new edition of Child (The on line text lacks the appended American version from Massachusetts, which is in the printed Child).
The Bodleian has another version, similar to the Bates broadside, with the same title, also in an 18th c. type font (Douce Ballads 3(27a).

Other versions are in Bronson and most North American folk song collections.
The American version in the DT is quite different from the original English ballad.

Sweet William's Ghost (Child 77) is a different song, but one reminds of the other.