There were sleevenotes with the original (vinyl, 1972) release of Shearwater, though for some unknown reason they are replaced in the CD insert (1991) with a piece about Carthy by Maggie Holland and John Tobler.  About his version of William Taylor, Carthy has this to say:

"Of all the traditional singers I have listened to, I think my favourite is still Joseph Taylor of Saxby-all-Saints, Lincs.  A few years ago, Patrick O'Shaughnessy of the Lincolnshire Association gave me a copy of a tape of his singing, and it has proved the steadiest source of inspiration.  The song William Taylor comes originally from him, although with thinking about it and singing it to myself, a few little variations in the melody have come in.  Some sets of the song have the last verse:

If all young men in Wells and London
Used young girls like he used she
Then all young girls would never marry
Very scarce young men would be."

Malcolm