Major E.O. Milne, the son of a Railway commissioner, was a soldier and railway officer who was stationed in Egypt in the mid 1910s to oversee the implementation of military rail works. He was an avid collector of Aboriginal breastplates later in life, with his collection now in the National Museum in Canberra. Milne amassed souvenirs during his campaign in Egypt, including ancient artifacts, and he sent these back to Australia, many of which were included in an exhibition at the Railway and Tramway Institute of Goulburn, New South Wales in 1917. It is likely that this flint knife was part of this show, as recorded in New South Wales Railway and Tramway Magazine, 1 February 1917, excerpt from http://rawsonplace.esmartdesign.com/rsd/corps-3.html): "A remarkable collection of flint and stone relics, the work of pre-historic man from the Nile Valley and the Sahara Desert, showing exquisite work in the manufacture of the implements which ancient man used in connection with his everyday life."
For a similar example see no. 172, pl. 43, p. 276 in Needler, Predynastic and Archaic Egypt in The Brooklyn Museum.