That was the thing to do when you did not trust banks and were afraid of the 'communists'.
A great Aunt died a week or so ago at the age of 94 and while I did not go the funeral, my mother passed on this anecdote told at the service. When Australia changed from pounds, shillings and pence to dollars and cents, Uncle Norm and Auntie Francis had rather a lot of pounds buried in tins in their garden in Oakleigh. They had to dig it up and take it to the bank and have it converted to dollars.
After the third visit, they were questioned by the bank manager as to where this mouldy and very old money was coming from. Must be a bit similar to now where banks have to report cash transactions over $10,ooo. The bank manager was suspicious.
I don't remember her very well. I can vaguely recall her complaining that the 'new' natural gas was not as good as that produced by the Oakleigh Gasometer. No heat in it she said. She was also worried that they would gas themselves as the smell was not as strong. I can recall visiting peoples houses who used gas for cooking and heating and the houses had a certain smell about them from the coal produced gas.
I am not telling you exactly where they lived as I need to go there and have a poke around in their garden.