[Greg]

I've used Novus #2 plastic polish on my 37-116 dial. It's not for the feint of heart.

• Just use a small bit of polish on a cotton swab. Don't want to get it "wet".
  
• The unprinted areas clean up easily. Work up to the numbers/letters/lines and stop short.
  
• Clean printed area by very gently rolling a swab it over the area. Remove residue with dry swab, gently roll.
  
• I then wiped it very gently with a microfiber cloth.
  
• The black ink seems to be tougher than the blue ink which seems to be tougher than the red ink... Your dial's only black, right?
  
• Experiment on an inconspicuous area, like the part number if it's out of sight.
  
• If it looks like the printing's getting lighter, STOP.
  
• Don't rush.
  

Try this at your own risk. Maybe I was just lucky.

Has anybody else done this?

I've also used Windex on my 38-2. Similar process, but more "dangerous" I think.
It started out as an accident. Windex mist drifted onto the dusty dial while cleaning the tubes .
The dust became blotches, so I had to clean it somehow.