'Kudzuman', the original poster to this thread (back in 2002), stated that 'Sovay' was also known as 'Newry Town' (Newlyn Town?) - probably not. 'Sovay' is about a female highwayman whilst 'Newry/Newlyn Town' concerns a thief who is taken by 'Ned Fielding's Crew' and subsequently hung (presumably on 'Tyburn Tree'). I believe that the generic title for the latter song is 'The Flash Lad'.
In my youth I was a great fan of both Bert Lloyd and Martin Carthy (still am, in fact!) and got the (very similar) tunes to these two songs completely mixed up. I recently heard a tape of Bert Lloyd, singing in a folk club in the 60s, and the tune that he used for 'Newlyn Town' is different from the one that he used for 'Sovay' - although similar enough to confuse a musical tyro like me!
Of course Martin Carthy recorded both songs - must go back to those recordings and listen to the tunes that he used.