Bob, I'll attempt to describe how these are made.
The second photo shows the trigger itself. It will fire the lock whether the trigger is set or unset. The first photo shows the "kicker", upon which the mainspring presses on the foot on its forward extension, and which is about half the thickness of the trigger's total thickness. The main trigger is filed away except for a bar running horizontally along the top edge. The kicker rests in this vacant area so that when the trigger is unset, it just floats and does not come into play. But when the trigger proper is pushed forward, that top bar on the main trigger presses the kicker down until it is caught by that little catch at the rear. That little catch or sear is tripped by an extension that you cannot see in the photos that runs back underneath the sear. The engagement of the sear is adjusted by the screw you see behind the trigger.
The mainspring on this trigger set has a hole through it so that the tang bolt can go into the trigger plate. Underneath the mainspring is a leaf spring going aft that presses up on the back end of the sear.
