If the plastic headlights are the same plastic as my 1996 Aerostar, they can be polished out. Same process as buffing paint, but you cannot get the plastic warm. Use very slow speeds, and light pressure with a buffer. But before you buff, sand with 400 to 600 grit sandpaper, wet, then work up in grits, 600, 800, 1000, 1500, 2000. Then buff with a rotary buffer, keeping the pad wet. I use Meguire's diamond cut cleaner, or heavy cut cleaner, and finish off with swirl remover. you can use just about any brand of buffing compounds you have, 3M, Mothers, whatever. Thay probably will all work in the headlights.
There may not be a lot of grills, and bumpers around, but I find it hard to believe Ford made only one Contour STV. If you choose, try to get new parts.
But again, it is your car. But if these cars are as rare as you indicate, does that not make them worth more?
The insurance company does not care if you fix the car, or not. All they care about is releasing their liability in this car, as economically as possible, by getting you to sign the check.
Is not the insurance company obligated to replace with "like kind and quality" ? But if you have already signed the check from the insurance company, you have released the insurance company from liability.