My Dad (Denis Healey) used to sing this to me and my sisters during our childhood in the 1950s. He was brought up in Keighley and I would guess he learnt it when he himself was a child some 30 years earlier. Our own home was on a leafy avenue in Highgate and the song brought with it a sense of the hardships known to families in the industrial North. Most of the meaning I figured out for myself except for the 'slarts'. I imagine the muck-splashed winders made it that much harder for the bum bailiff to see in.