Yep, Australian for the No1Mk3 The broad arrow should mean it was British property at some point but there are a few different meanings of broad arrows. If it isn't surrounded by other marks the broad arrow is simply a British acceptance stamp, New Zealand used the Broad Arrow and NZ, Canad has a Large C with the arrow inside the C
9 43 =Sept 1943 production
Slaz 43=Slazenger, bayonet grip manufacturer
Mangrovite 43= Scabbard manufacturer
OA= Orange, bayonet manufacturer
MA over 1907 over l = Australian standard 1907 mark
Xoa= Probably the X is the bend test next to anothe OA for Orange.
I own firearms not to fight against my government, but to ensure I will not have to.