I'm so glad that Pat Cooksey immediately attributed his excellent song to Gerald Hoffnung. For the record, Gerald Hoffnung performed the story abour the bricklayer "respectfully requesting sick leave" in the Oxford Union on Dec 4 1958. If you look up "Hoffnung bricklayer" in Google, you can easily find a transcript of the story, and you will also find that a CD is available with, amongst other treasures, many of his wonderful funny anecdotes, and this one is included.