Ah! I actually took the words from here;

They'll never believe it's true

I assumed that the notes were those in the CD booklet. My own copy of the booklet is apparently from the original release AK2 on Andy's own label from January 2000. These notes too do not include the words "Boiled in Lead". The Appleseed copy was released on 27 March 2001.

And I was at the following performance, though not part of the conversation;

Subject: RE: J. Moulden or Philippa: Two sisters
From: Ross Campbell Date: 16 Nov 15 - 07:59 PM

I used to sing The Two Sisters, mainly from Clannad's version, with a verse or two from Sharp's Appalachian text which seemed to fill out the story. I sang it once when Andy Irvine was the guest at the Lane Ends Folk Club, Wesham, near Blackpool.

He came over afterwards to say that he had set the tune to those words, but that Clannad and others who recorded the song had either not known or had somehow failed to mention that. He had always felt slightly miffed about the missing attribution, but somehow never got round to recording the song in that version.