This comic song based on a vernacular expression was written by John Cotterill of "Chinese Laundry Blues" fame, and was recorded by George on October 13, 1932 for Decca. He also sang it in his second film Off The Dole, which was released in 1935, accompanying himself on the banjo rather than the ukulele.
Although the expression or similar has often been used by costermongers, it goes without saying that here it is given a sexual connotation, and Formby probably went as far as he could have gone in the 1930s without being rebuked or more likely censored. It may be coincidental, but "Any Old Iron?" which was written some twenty years earlier is passingly similar, though no one appears to have raised the suggestion of plagiarism.
Suggestion credit: Alexander Baron - London, England, for above 2