Hi, I saw your post. I have friend who can clean this dial under a microscope - if you are willing to take a chance. I personally would leave it, BUT (before you laugh this off) this guy performs this service for the most influential dealers in the USA and the world. I just had him clean a Breitling Duograph split second dial from the 1950s, and it came out spectacular. He can minimize those dark spots. He will NEVER do anything that will put the dial in jeopardy. His work is amazing and his techniques are propriatary - sort of like people who clean old paintings: the don't repaint them, they simply have ways of cleaning them that bring out the original intention of the dial. Honestly - I would probably leave the dial, but I can tel you from personal experience that this watch artisan can do wonders on a watch like this, and has worked on watches at this level many times. PM me if you would like more information.