Nayook, just south of Noojee is good enough for me. This is at the end of the path south of the trestle bridge before it hits private land and I was amazed by the amount of earth moved to make this section of line. Well done @Valvegear and the floor is open.
I think that "Somewhere on the South Gippy rail line" may be considered too broad an answer. We could knock it down very quickly if we go line by line.
Thanks for having a tentative go. But not Healesville. Trains actually run along this line daily. Although admittedly, that wasn't the case when I took the photo.