Crotalus Pricei (Western Spotted Rattlesnake) vertebrae
Approximately 24 vertebrae 
1-2.3cm approx size
Snake of least concern (NON CITES) nor a native snake to Australia. 
Snake bones are one of the hardest things for me to track down, ethically (responsibly). I know you can get an entire articulated snake from China fairly cheaply, but I have little interest in obtaining them. 
I went through a reptile handler and collector in the USA who rears, collects, and breeds reptiles as a hobby. They also rear invertebrates, including dermestid beetles. All reptiles that pass naturally in their care are fed to the dermestid beetles. I was able to purchase the bones and import them. No snakes died just for commercial use. This is a limited product. 
You may use these bones in your art, add to your collection with no permits required.