The idea behind "My Girl's a ..." could go back a ways. This song was mentioned in James Joyce. Lyrics posted by Jim Dixon - "My Girl's a Yorkshire Girl."
Look at the chorus- Different melody to this music hall song.

My girl's a Yorkshire girl-
Yorkshire through and through.
My girl's a Yorkshire girl,
Eh! by gum, she's a champion!
Though she's a factory lass
And wears no fancy clothes,
Still I've got a sort of a Yorkshire relish
For my little Yorkshire rose.