First, I doubt very much that the song that Ar Wysg wanted was SWEET WILLIAM'S GHOST. There are several versions of SWEET WILLIAM'S GHOST already posted at Mudcat, and none of them have anything like the lyrics that Ar Wysg quoted.

Furthermore, the "podcast" that ClaireBear's link points to does NOT contain SWEET WILLIAM'S GHOST (or FIDDLER'S HILL either). The only "folk" song in it is HOLSWORTHY PETER'S FAIR, which comes from the album "Sweet William's Ghost"—and it clearly isn't the requested song.

FIDDLER'S HILL seems more likely to be the song that is wanted, although I can't find any lyrics or sound samples online.

FIDDLER'S HILL (Words, Peter Bellamy; tune, trad.) is on the following albums:

Peter Bellamy, "Tell It Like It Was," 1975.

George Deacon & Marion Ross, "Sweet Williams Ghost," 1972.

Loscoe State Opera, "Dawn Bird" and "Live at Stainsby"