Film and radio:

Short scenes  in RAW firnat from Michael Drury of Michael Smith's landing at Darwin or download from https://drive.google.com/open?id=1b8wFLSIt2PJmRtAcY21ClQyf1VSE2HpI

Michael Smith's website http://www.southernsun.voyage/currentadventure notably this link which shows the Sea Bear in flight

Stefan Drury's Youtube posts https://www.youtube.com/channel/UCG1HLA8IEqZ09_C_7u5tUjQ and notably about a third of the way through https://www.youtube.com/watch?v=FMXg1NQ3sfA&t=442s (Michael's landing at Darwin)

also https://www.youtube.com/watch?v=lYOZgLvb5nE (Michael Drury's tribute flight Point Cook to Darwin, following the route of Wrigley and Murphy, who surveyed the route by air for the Smiths.

https://www.thegreatestairrace.com/ has details on the documentary film produced by SBS mainly on the England to Darwin flight

Film of original flight https://www.abc.net.au/news/2019-12-10/great-air-race-flight-from-uk-to-australia-centenary/11782024

There is an excellent radio podcast on the Smith flight, downloadable from https://www.abc.net.au/radionational/programs/the-history-listen/the-great-air-race/11543712 and featuing Australian astronaut Andy Thomas and South Australian author Lainie Anderson.