Broken plastic causing stuck balls in shooter lane

There's a broken plastic on the upper left side of the playfield as part of the separation between the shooter lane and the main playfield. It's usually not visible because it's covered by another plastic, but it's used to help guide the ball.

The top part of it (which should usually be connected to the bottom part, except the heat from an incandescent light melted it to the point where it became separated) is only secured by one screw. When the ball hits it, it can move a bit, and eventually it can get to the point where the broken edge sticks out into the shooter lane, and a slow plunge can get stuck on it. If it sticks out far enough, it could potentially block the ball from being plunged into play.

I should be able to either 3D print or laser cut a replacement for the broken plastic, but I'm going to take a couple of parts home so I can make sure I get the dimensions right. So it'll be unplayable for a couple of days until I can make the replacement part.