WorldCat.org indicates that Leeds College of Music and the National Library of New Zealand have copies of the sheet music for DELANEY'S DONKEY. It was written (words and music) by William Hargreaves, and published in London by Francis, Day & Hunter in 1921. It's also included in a book called "Songs of Ireland" (1982) by Val Doonican, and in "Francis & Day's Album of Famous Irish Songs."