Just checked my vinyl copy of Last Waltz, which I should have done beforehand: credited to 'Dylan' only. I'm sure though that I've seen RM credited elsewhere: it's not the sort of thing that I'd imagine. Incidentally, I recently got a DVD copy of Last Waltz, which includes a lot of extra stuff: mostly interviews with Robbie and Martin S. Learned, for example, that the opening song in Last Waltz, was in fact the final one performed on the night: some other fascinating insights, adding much to the appreciation of the film.

Re All My Trails: I'll leave that one to the musicians among us.