We can now date 'Paddle', 'Kangaroo', 'The hardware line' and 'Girls of ------ Road' to no later than 1865.

The Word on the Street website (courtesy of the National Library of Scotland) has some dated broadsides which themselves list a 'Catalogue of Newest Song' - this one for example (scroll down for the list).

Jemima Brown also appears, again with an 1865 date.