From Michael Kilgarriff "Sing Us One of the Old Songs":
" 'e Don't Know Where 'e Are". Written by Wright and Eplett 1890. Sung by Gus Elen. Parodied as "There Goes the Bloke Who Dunno Where 'e Are" in an 1894 version by Alec Hurley and sung by Marie Lloyd in Pretty Bo-peep at the Shakespeare Liverpool. Yet another parody entitled " 'e's Found Out Where 'e Are" had words by G. Wallice Arthur (who was also the performer) and music by Fred Eplett. Jack Jones's reply was sung by Arthur Rigby.

So there we go. The catch-phrase would seem to pre-date both the Patterson poem and the song. It would seem to be Cockney or "stage Cockney".
Cheers, Joy 'o's found out where she are.