Hi Mike,
I know exactly what you mean, but I don't think anyone this side of the pond would put any store on any of Ewan's songs or notes to albums, as with Bert. However, 'Travellers' Songs from E & S' is a different kettle of fish and I trust the songs in that, if not the notes so much. You would know more about that than me.

Quite often nowadays when we decide to include a song in our repertoires, we've already heard/seen dozens of versions and mostly our new version is a mixture of others, and even sometimes the odd new material will get included.

Only someone inexperienced would expect anything sung by Ewan or Bert to be a straight copy from tradition.