Don't know what sales were like in Aussie but here in NZ a lot of BSA Hunters in 7x57 were sold and come up for sale second hand occasionally. They usually fetch good prices but would make a good base to customise if a little shabby. The beauty of the Hunter model was that it was made in a medium length action just for the 7x57 cartridge.

They are a Mauser derivative, I had one in as new condition myself and it was a beauty, very strong and accurate, stupidly I sold it as I had other rifles in use at the time.