Australian W15D Hallmark Brooch Question

by Paul
(Victoria, Australia)

I recently won bought 4 Antique brooches at auction and managed to figure out the markings of two of them but the remaining two are marked W 15 D and I have been unable to figure out who made them and in what year. The are from Australia. All help is appreciated.

The two I am talking about are the bottom brooch and the second from the top brooch.