Australianicon ownership marks on the receiver ring and the butt. One of our Australian members can tell you exactly what those represent.

Perhaps the "22" refers to this battalion: https://en.wikipedia.org/wiki/2/22nd...ion_(Australia) but purely a guess on my part.

Stock has been stripped relatively recently by the look of it which is a pity.

Tracing where your relative served in WWII might help pin something down.