I've repaired plastic before by cutting out a piece of perspex sheet, filing it to shape and supergluing it in place. In your case, depending on the length of the stab wire, you could glue it to the side of the remaining piece.
a different approach would be to melt two holes through the remaining piece, and push some stiff wire through one hole, then over the top of the remaining piece and in to the other hole. you can taper the wire into a point over the damaged area to prevent any movement.