Bottlebrush Sawfly larva (I think)

According to Lepidoptera.butterflyhouse.com.au this is the larva of a Bottlebrush Sawfly (Pterygophorus cinctus), which is in fact a type of wasp and not a caterpillar/butterfly at all. I'm not sure if this is actually what this is, but it's the closest I can find to this picture, though I don't think I've ever seen any adult forms around. If anyone has any other ideas on what this is, let me know.
My Mum and sister found one around this time last year and I tried to raise it but it escaped...