I have a rather low mileage '67 with A/C. The headlight and cigarette lighter knobs are like new, but the radio, A/C knobs, etc. have lost their black paint. Since the paint is a circle, how do I get a clearly defined paint line? I thought about spray painting them and then using lacquer thinner to wipe away the excess paint, but the recesses where the paint ends are going to present a problem. If anyone has a solution, also let me know what kind of paint and sheen I should use use. The other knobs appear to be glossy. Thanks.