Based on the Dutch M1898 Naval Cutlass made by Hembrug. The USN M1917 Naval Cutlass was based on the Dutch M1898 Naval Cutlass as well. I forget the exact details, but when the Navy went to order more Navy M1860 cutlasses in 1916 as part of their WW1 run-up preparations, they got talked into accepting Dutch M1898s instead, since that was what the manufacturer, Lilly-Ames, was making. The official USN M1917s are simply stamped "USN" on the ricasso.
The "M1942" cutlasses of the WW2 era were not made for the US Navy initially. When the Navy went to order more M1917s in 1941, Lilly-Ames was making Dutch versions for the Dutch Navy/Army/Police forces. Viking and MILSCO were making them (with stamps) for the Dutch East Indies (DEI) forces.
The Navy accepted the Lilly-Ames versions as substitutes, since there were only minor differences. One of the Navy requirements was that the handle wood be dye black rather than plain wood as the Dutch version being made. The USN ordered Dutch M1898s of 1941 had no notches in the basket (removed in the heiho conversion) and were totally unmarked.
Well, the Netherlands fell to Germany and the DEI fell to the Japanese. No buyer, no shipping. In 1942, the war department was talked into buying them for use by landing forces as machetes and last ditch personal defense weapons, hence the reason they are sometimes referred to as M1942s.
The unmarked Lilly-Ames and the viking/MILSCO versions were shipped out, supposedly mainly going to troops headed to Guadalcanal.
The "heiho" swords were the Dutch M1898s and locally produced versions already in theater when the Japanese captured the DEI. The captured M1898s were converted by the Japanese by removing the basket hilt and shortening the blade and scabbard. The heihos found in the US are war booty bring-backs.
The OP's sword looks to be a DEI locally made M1898 converted by the Japanese to be a heiho. The AUS stamped into the ricasso has no reference to the US, army or navy. Maybe refers to Australia in some fashion or has some other significance.