Slide frame help

[Babylon 5]

Ok so I'm new to autocockers and bought this pump project that needed new o-rings and a sear pin and trigger return spring. So my question is how does the trigger spring stay in place? I go to put it in and it just pushes straight through. It's a benchmark frame so is it missing a bumper for the spring to press against to return the trigger?

Thanks in advance.

[Meleager7]

you'll probably need to find a replacment for that rear stop grub screw, thread size and length , i will leave up to the more season cocker vets to answer!