Harper's Ferry patchbox release install

[mtmannh]

I cannot for the life of me, figure out how to install the "v" shaped spring in an 1803 HF from Pecatonica. I understand the push button pin comes from the top of the buttplate but does it push down on the spring and if so, what goes on the patchbox lid that catches the spring? 

[smylee grouch]

I put a small stud in the end of the lid, rivit it on the top side and file a notch where it goes along the spring so the spring falls into the notch. When you push the button it depresses the spring and disengages the spring from the notch.