WWI era double-sided photo pendant featuring sailor and soldier

World War One era double-sided, circular pendant locket containing the portraits of the head and shoulders of an Australian sailor on one side, and a different Australian soldier on the other.
The greyscale image on the front shows a sailor wearing his white cap with a black tally band on which the name 'HMAS Tingira' in written in contrasting thread. There is a rosette or cockade attached to the left, securing the tally band.
The portrait on the reverse shows a soldier dressed in uniform, with the rising sun collar badges visible on the lapels. He is wearing his peaked cap with leather band.
The circular border around the edge of the portraits is made from gold toned metal.. A thin piece of celluloid covers each photograph.
There are no hallmarks or maker's marks.
There is a gold metal spherical fixture at the top which has an affixed loop through which a chain could be threaded.