While I am sure it was very valuable to your mother, today there is very little market for silver plate tea/coffee sets. Mid 20th Century they were heavily produced, and are too common on the market place today. Yours was made in Australia, and I would estimate that with a good cleaning, and if no silver loss or other damage, it might sell for $85 to $100.
Based on the markings and images this set is not antique and is a mass produced example. The market for silverplated sets like this is currently very weak, sets in good shape often go at auction for under $100.00
Re: Antique Tea Set
While I am sure it was very valuable to your mother, today there is very little market for silver plate tea/coffee sets. Mid 20th Century they were heavily produced, and are too common on the market place today. Yours was made in Australia, and I would estimate that with a good cleaning, and if no silver loss or other damage, it might sell for $85 to $100.
Re: Antique Tea Set
Based on the markings and images this set is not antique and is a mass produced example. The market for silverplated sets like this is currently very weak, sets in good shape often go at auction for under $100.00