[kingsley]

Possibly the gilt may have just worn off. From the 1890s to 1912 there were quite a few regiments that wore badges in both brass (or gilt) and WM. There was an army order in NSW authorising it but I can't tell you the reference.
Bob Gray's collection has some of the 1903 Corps badges in WM when they were normally brass.
All of the badges you illustrate were 1901-03 NSW but I still don't know the origin of the badge. My understanding is that they ordered an existing badge from a catalogue like my early Gaunt's. Which UK regiment wore it first and when?
The high quality mystery ' L V Asylum Festival' badge illustrated is dated 1869. I have asked about it before on the forum and had a few replies about the possible meaning of "LV" and the motto (which is the same as the Bank of England), but not about the origin of the badge design.