Have been reading this thread and thought I better add my 2 cents worth as 1) I am an Aussie, 2) I live in Australia, 3) am ex- military (Army), and 4) have been collecting Aust wings for a while.
All Aust Military (Army- AAAvn Navy - RAN, Air Force - RAAF) have both Metal and cloth wings. I can post photos of all but that is against the forum rules. The RAAF first started using metal wings in about 1947/48 with the kings crown on top. Then when the Queen took the thrown in 1952-53? the crown was changed to the Queens crown, but not until 1954. I have only seen dated hallmarks from the late 1940's and 1950's, it appears that the dating was dropped after the 1950's.
So, RAAF have been using metal wing from the late 1940's up to the present date.