See IanC's post above for the approximate publication date of the first example mentioned by Mrs Holroyd.

Roy Palmer (Bushes and Briars: Folk Songs Collected by Ralph Vaughan Williams. Lampeter: Llanerch, 1999, p 178) refers to an 18th century slip song, 'The Maiden's Complaint for the Loss of her Shepherd' as the earliest known form of a longer song from which the 19th century versions presumably derive. Copies are at the British Library and in the Madden collection at Cambridge; approximate date 1790.

The Roud Folk Song Index lists the song group at number 1046, and includes a set in Christie's Traditional Ballad Airs I, 1876, 222-3, which would likely be more closely related to the earlier form; textually, the resemblance to Holmfirth and its closer relatives is fairly slight.

The question of pronounciation was dealt with in this (recently revived) thread a couple of years ago; but with the posts currently out of order, it may be difficult to see that. Hence perhaps the tendency to labour the point.