It is also dateable quite precisely by the reference in the first verse to 'the exhibition', meaning the 1862 exhibition in South Kensington. To remove any possible doubt,the 1862 building can be seen in the background to the Concanen & Lee lithograph attached to Malcolm's 19 March posting. Part of this building later got transported to Bethnal Green,where it houses the Museum of Childhood.
I find Clifton fascinating as character-singer and songwriter. One of the pre-sound-recording artistes I would have most liked to hear.