It's a Britishicon made bayonet that has found its way into the Australianicon ordnance system and has been arsenal refurbished in Australia. I have a WWI Wilkinson P1907 that has been refurbished to mint condition with a pair of 'AUSTRALIA' marked grips. I think it also has an Australian scabbard and other than the blade, the metal is parkerized. I think it may be a post-WWII thing as I have a 1943 Lithgow Bren gun FTR'd in December 1950 that not dissimilarly has been fully parkerized plus new woodwork fitted.