The best place that I can think of for finding old .32 rimfire is gun shows. Yhey would be the best place to start. Then maybe you might find a guy that makes them or has a surplus of them from a gun show. As far as online buying I am not sure.
"I know what you're thinking. "Did he fire six shots or only five?" Well, to tell you the truth, in all this excitement I kind of lost track myself. But being as this is a .44 Magnum, the most powerful handgun in the world, and would blow your head clean off!" - Dirty Harry