Phil Ledgerwood offered chromed posts a few years ago, but said that the quality wasn't good enough so he stopped doing them.
The current coating on new Morgan seems resiliant, but don't use any sort of polish or it will shine the surface and become patchy.
My 2005 has a coating which is best described as thinned grey hammerite. I doubt it was a diy job in the first three years, so is probably factory.
