Effie - the version I learnt in the early 50's was started out:
'We three spivs of Mersey Square.' Spivs dates it to the war years and Mersey Square is in Stockport - local reference, as we'd probably never heard of Leicester Square. The rest was (more or less. I haven't heard it since 1958) 'selling nylons tuppence a pair, they're fantastic, they're elastic, guaranteed not to wear'