Track looks familiar to me. it could be a Gippsland Victoria track (Maybe Ottrim near Korummburra) by the look of that sandy loamy soil, my next guess would be Briant Park, Smithton Tasmania (except the corner /spectator fence don't align to my memory).
as for rider and the era he would be a A grader with #27 on the plates, thats as good as i can go. he looks tall in the bike?