It looks as if you lost the tiny pin that holds the spring in place. They are just press fit into the inner body. Some just slip right out, while others can't be removed unless you grind them out and destroy the freewheel. I might be able to provide you with a replacement spring (although even though your spring is bent it will most likely work) and pin. But, this is your opportunity to make an upgrade, if ever so slightly.

Atom would eventually ditch the two notch inner body in favor of a splined inner body. Regina went to the same system so the same tool removes both models. Probably about the same time, Atom did away with using the tiny wire push springs in favor of the brass leaf push springs. IMO, the leaf springs are a big improvement over the wire springs.

Thanks! Glad to help out.