It is possible to get a frisket for the " pop art" dot shading but you would be making a small silk screen.
I had the same issue with Amazing Spiderman and in the end I airbrushed the base on and then "hand dotted" the graduation through.
Its impossible to tell in most areas I did..
Wow, I can't even see where the repair was made! There is no chance of me being able to touch-up the wear on my playfield, I think a decal is the best option.
Cheers,
Matthew