If memory serves me well, and it doesnt very often, the fender is all one piece and fenders used to be available and fairly inexpensive.
Thee are also fab shops that will rebuild to new. Just gotta find one close. I used to send out pieces to a local body shop and they came back better than original. Of course they took there time to buff and sand till the glass was like ice, All our wrecked class 8's that had fiberglass were sent to the body shop at 1/3 the cost of dealer parts and service.