I had missed that footnote: 'Also in ms. by Captain Martin Williams, Ostrea Lake'. Creighton was in Ostrea Lake in 1935 and took a photograph of Captain Williams, but apparently made no sound recordings there. 'In ms.' might suggest that he wrote the words down himself, but that is only a guess. The Creighton Archive lists only the photo; perhaps the ms is somewhere among the general correspondence. At any rate, it seems unlikely that his tune, assuming he had one, is extant.