It's bad enough to see the criminal mechanical mischief that passes for gunsmithing on an almost daily basis but when one sees something like this, especially considering that the replacement part is actually readily available, it makes me think about taking up another line of work. Maybe something less stressful, like Komodo Dragon dentistry, or training Tiger sharks to eat out of my hand like my neighbor's Koi do.
This Parker had a failed sear spring. The correct (and easy) method of repair would be to remove the remaining locating post from the frame, fit a new spring, verify no interference of the new spring's free leg with the shoulder on the sear (and correct if needed), reassemble and go about the rest of your day. That method was clearly too easy for this guy. He drilled and tapped the frame to accept a screw and washer that held not one, but two pieces of leaf spring to drive the sear. It's also readily apparent that these two pieces of spring are exactly that, pieces broken from already-existing springs. Quite an interesting arrangement, with the first very light leaf stacking against a much stiffer "helper" spring and then both coming into contact with the remains of the original spring. Brilliant. Why didn't the factory think of this? To add insult to injury, he also literally knife-edged the sear noses, which I can only surmise was an attempt at a "trigger job".