The ring was resized and part of the mark is missing (most likely gold standard).
Nevertheless,the combination of crown and lion passant (both facing right and left) is known to have been used by Australian silversmiths - jewelers.
The crown is Queen`s crown of Queen Victoria. Cannot tell if they changed to King`s crown of King George V and VI which was done on e.g. regimental badges.
Example bellow is on Australian gold ring and a mark used by an Adelaide silversmith (not L&W).
You can contact The Gold & Silversmiths Guild of Australia at http://www.gsga.org.au/
and enter ``Australia`` into the search engine of this page (top right).Good luck.