just thought i'd update to say that the song is on Alasdair Roberts new album "No Earthly Man" & in the liner notes it says that it is (as Nerd had said) adapted from Andy Stewarts version for Silly Wizard, though the lyrics in Roberts version are "mostly a composite of three sources.." the Silly Wizard version "Carlisle Wall", on their 1976 self titled LP, .."a version recorded in 1975 by the Aberdeen born singer Lizzie Higgins, & particularly in regard to the final dialogue section, an English version by Shirley Collins on her 1967 Topic Records LP the Sweet Primeroses".

thanks again for the help, & in case anyone is interested Ali Roberts is doing some gigs in the UK & Europe from then end of March to the end of May. dates here:

http://www.dragcity.com/tours.html