|I have never seen one - but Riccardo may know. Riccardo gave me the address of the Cemetary offices for my grandfather's town. On a sad note (for me anyway). My town removed all the old graves to make space for new ones. All my ancestors are now in a mass grave. I hope your town did not do that.|
Do you have a link to the Australian one? I would love to have a look.
I think that is a fairly common practice but it is not always consistent --- I think it is done for both space and also due lack of funding (perpetual care) to maintain the crypt or grave. My cousin's husband told me that in the City of Bari you are rotated into the mass burial vault in 8 years (I think you still get a little box) due to space limitations.
In my Dad's hometown of Corato, my Uncle who died in 1932 still has his crypt, but my Grandfather (1941) and my Grandmother (1931) are in the Ossuary (mass burial vault). In San Giorgio Albanese my Great Grandfather (1936) still has his original burial vault. Same was true for my other Uncle (1957) in the city of Foggia.
What is really neat are the photos on the graves which was a wonderful experience for me as I didn't know what everyone looked like as there were not too many photos available.
Maybe Riccardo can expand upon this as I am not the expert, and as I said it seems to be very inconsistent in my personal situation.