I have one OEM Air Dam for a 70's vintage 320i S package car, this was made in our family owned shop for BMW of North America, in great shape, never mounted on a car. No scratches, drill holes, nothing, very clean.
Also, I have one Air Dam for an early 85 - 87 ish BMW 318 sedan, also made in my shop in 1985. Never mounted on a car, no scratches, drill holes, clean as a whistle. Both air dams are made of polyurethane elastomer, very tough stuff, very effective aerodynamically, looks great on a car, price is reduced to $150 each, I can be reached at the numbers below.