I went to a friend the other day and glass bead blasted some parts I already removed from my bike. The result was amazing and I will do a test with zink spray from an ordinary spray can. It is supposed to give a matte dark gray surface. I consider using it alone on the swing arm and frame if I am happy with the result. Electroplating of some kind will probably give a very good result but I want to try the "spray can road" first. I can always redo it in a few years if I don't like it. I have learned a lot so far.