Steptoe and Son S06E08 - Cuckoo in the Nest

A brash Australian called Arthur turns up claiming to be Albert's long-lost elder son and, to Harold's horror, Albert believes him, agreeing that Wallaby Jim of the Islands as Harold calls the lazy, cadging interloper, should be his heir. Harold moves out into a shabby bed-sit and struggles to make a living with his hand-cart. Then his father visits and asks him to return. Arthur sold the horse and cart and disappeared. Eventually Harold agrees and, as they turn the corner, they see their horse and cart coming down the road.