Metal Tudor QB

[KTown49er]

I just bought a metal tudor QB off of Ebay and received it today. It is apparently missing a spring of some sort. The trigger mechanism at the bottom is spring loaded and functions but it is not connected at all to the throwing arm. The throwing arm simply revolves around independently.

Can someone let me know how I can repair this item to give it a try (or am I just missing something?).

Please post pics of a working metal QB if you can and I'll try to post some pics later of the item I received to see if or how it is different.

Thanks for any help you can provide.

Allen