It's hard to tell if it's Aussie from the picture. I can see what appears to be a "DP" stamp in the top of crosshead rail. But, a few things seem to suggest that the tripod at least saw service in Australia since British tripods were supplied to Australia and modified. The evidence is the black paint on the handles and the notches on the feet. I can't see the feet but Aussie manufactured tripods have spiked feet as in this image
http://www.vickersmg.com/images/Aussie_Front_Foot.jpg. Australian manufactured tripods are also marked "RT" for Randwick Tramway and, if I recall correctly, MA with a date in the early 1940s. BTW, I've had about 10 tripods and found original as assembled, non-DP marked Australian tripods some of the best in the market. Is the socket head steel? Again, if I recall correctly, toward the end of WWII the Brits switched from bronze to steel socket heads. Ask about the bottom of the feet (pads). It almost looks to me, when I zoom in, that the foot is flat to the floor. It might be an optical illusion but I saw a DP marked set of tripod legs that had the spikes ground off. I have no idea who did this.