Kombi, can be done, but it ain't as easy as it sounds. First step is to slug your bore and see what you have. It's probably in the neighborhood of .318. Most of the available 8mm moulds cast .325 or so for the newer 8mm barrels. I would not want to size down that much.
There are moulds and sizers available in the .320-1 range for the .32-40 and .32 Special. They would work in a .318 bore, but they are a lot lighter than the Commission rifle bullet and most are plain based.
Here in the states, I can have a semi-custom mould cut and a custom sizer, and get change from a hundred dollar bill. I have no idea how you would go about it in Australia.
