Over the last couple of years there have been a few threads about songs from these English performers, and there are a couple of songs in the DT (without tunes as I recall).
I've just managed to borrow THE book of their music 'The Songs of Michael Flanders and Donald Swann' St Martin's Press, New York, 1977, Library of Congress 77-82055.
Their better known songs include 'Have Some Madeira M'Dear', 'The Gasman Cometh' plus sundry songs about animals which I don't know - Armadillo, Elephant, Gnu, Hippopotamus.... Let me know if anyone would like to submit the notation to the Forum and I will scan them for those interested.
(As an aside the lyrics from Michael Flanders in 'Have Some Madeira' are in my opinion some of the cleverest writing in the English language that I've ever seen).
Regards, John