The Wurzles?
My feeling is regional accents (of whatever country) will always add to the feeling and authenticity of a song - thinking Lindisfarne, Amy MacDonald, Mary Hopkin etc, and good examples in previous posts.
What can really irritate are blatant put-on accents (UB40’s mock Jamaican springs very much to mind) - exception is Chrissie Hynde’s luscious singing voice which has always sounded distinctly accented French to me, although I believe she comes from Akron Ohio......