Great story.

My old freewheel fell apart, and lots of tiny balls fell all over the place, most of them irretrievably. I reassembled the freewheel with as many as I could find. It was fine. That's very different from a pawl spring.

I can't remember what material people used, but I've read stories of people fabricating their own Sturmey-Archer pawl springs out of some kind of wire.