Hey Glyn,
Here's a thought.
Sorry, please bear with me, a story comes along with the idea:
I was interested in two of my E29 winches having a natural bronze finish--and after researching the chroming process, found that they can also be "de-chromed" by reversing the electroplating process. So after buying some muratic acid and using a 12V battery charger, I tested out the internet receipt. While it did remove the chrome, the resulting raw metal was patchy at best.
So I took them to a motorcycle chroming shop--with the mission to have them re-chromed. The shop owner told me about the dry-powder coating process that is used for most motorcycle parts now days--and is available in ALL colors and finishes. The part is sand blasted clean and then the powder is electrically applied and permanently baked on. So I chose a bronze color and invested the $35 for a test run. I was so pleased with the result, I had two others "bronzed". While the coating is permanent and should last at least 5 years--should it wear through--the underlying natural bronze metal will show through--and should look fine. Here is a pic of the three bronze ones next to an original chrome one. I pass on the info--as the variety of colors and texture is endless--there are even metal-flaked or metallic colors. Check it out--its cheaper than a new winch or Genoa slide. Good luck!