In all of my searches through collections I have never come across anything in the British Isles that relates to the Careless Love stanza. I was singing this song back in the early 60s before I became fully immersed in English trad song so I would have spotted anything had I seen it and noted it down. Personally I would treat Peggy's comments in the same vein as Bert's or Ewan's. Peggy was interested in singers and immediate sources but not really histories to the extent that we are.