That is obviously a version of the old folk ballad "Rosemary Lane". There is a version of it in the Reverend Sabine Baring Gould collection. There is probably a version of it somewhere in the Child collection, although we had better get one of our Mudcat folk academics to confirm or debunk that claim. Under the title I have given above, the song was recorded by Bert Jansch, who I believe may have got it from Anne Briggs. There are many versions of it - and yours is an interesting variant. Thanks Jude L.