Where to begin.
For starters it cannot be 1947 as the factory that made them opened in 1948, so it probably 1949 - that said, its is a very early model as it has the metal rather than the plastic impellor. The drain hose has been replaced at some point.
These are very simple machines although when they were introduced they were a Godsend to housewives. The video below will tell you how it operates.
How much is it worth? Well the simple answer is what someone is prepared to pay. These models still crop up from time to time in the UK but they will probably be much rarer in Australia. But it would only be of interest to a collector or someone interested in living a "retro" life or perhaps a props house for set dressing.
Al
