The windscreen brackets on my Roadster have a very shiny grey lacquered appearance. I had no reason to think this wasn't standard, but over the last five years, every Roadster I've examined has had dull flat grey A posts. I began to suspect that mine had been 'refinished' and last night I had a much closer look. They have been carefully masked and blown over on the car with some sort of acrylic lacquer. The give-away is under the bottom windscreen rubber, where the finish is dull and grey. So there you have it. Another riddle solved.