I haven't shown it to Steve Roud yet; I will make it a priority to do so, it will be interesting to see what he makes of it.
Steve Roud tells us that we should be concerned with the 'process' of how a song changes in the oral tradition rather than focussing on the 'origin' of the song, so in this case does that mean that we should be looking at the 'where' and 'how' of changes to what might be called "an older set of traditional verses" occurred rather than thinking of the 'who' and the 'when'?
I don't think that there was any date or author's name on the Terrible Down manuscript that I acquired and, anyway, I cannot seem to find it at the moment.....