Fatty Finn is a 1980 Australian film, directed by Maurice Murphy and starring Ben Oxenbould with Rebecca Rigg.
Set in inner-city Woolloomooloo in Sydney, New South Wales in 1930, the neighbourhood nice guys are led by Fatty (real name Hubert Finn), an ambitious 10-year-old with an eye for making a quid.
From shady frog jumping contests to a fixed goat race, Fatty uses his enterprise to raise enough money to buy a crystal set (radio without a separate power supply) that's worth seventeen shillings & sixpence (17/6), more than his Dad is able to save up in a year.
He complained about interference from the film's producers, John Sexton and Yoram Gross, claiming Sexton in particular wanted a lot of changes, but changed his mind after David Puttnam praised Ellis' original draft.
The movie was set in Woolloomooloo but the area had changed a lot since then so was shot in and around Glebe.