In 1993, this fairing seemed brand- new to me. It'd be interesting to see how well it has aged since. Polycarbonate may be unbreakable, but it is not resistant to scratches, and other consequences of daily/ frequent usage. Still, I suppose, that --especially were this a commercial product-- it'd not be hideously  expensive to replace a badly- scratched, or -stained fairing body with a new pre- cut replacement part, to be attached to the frame in place of the old one with Pop rivets, or other supplied fasteners.
    I say explicitly "commercial product" because it seems to possess a lot of appeal and suitability for lo-tech production. Bought in bulk, polycarbonate sheeting is only moderately expensive, ergo the finished product, a D-I-Y kit, ought to find plenty a buyer.
    Perhaps that'd be something to consider now that boxy homemade Coroplast fairings seem to be all the rage (a waterproof, corrugated plastic "cardboard" available in a variety of flute heights, wall thicknesses and pastel colors, that can be worked with, cut and bent as were it ordinary corrugated cardboard; trade name Corex and others).