I have that Coronet. The polish really darkened the blue (mine is molded in blue gray, but I've yet to see anything metallic about it). I have a 1969 Cougar that is molded in orange and has a mold line. I have thought about sanding the mold line with 8000, 10000 and 12000 grit sanding pads. I plan to experiment with scrap orange plastic first.