If you paint fan cels, what's your preferred 
method for removing paint that accidentally gets 
somewhere you don't want it to be? You might try 
it on removing the stray stuck paint. Using 
something metal (like the edge of an exacto 
knife) to scrape it up would probably scratch the 
plastic, but if you're careful with a wooden 
toothpick, that might work.

As far as the touch-up goes, if you're 
comfortable enough with your color-matching 
skills, you might do what you want to, perhaps on 
a separate layer behind. If you ever resell, you 
should be sure to mention whatever corrections 
you've made.

Good luck!