Hmmm i think i would just dab a little Testors silver over that--bet you can't tell after the playfield glass is on. Looks like an operator was working on it and laid his cigarette there.

Im not sure about leaf adhering to plastic? It's usually used on metal (which is a pretty non-porous surface). I think your going way beyond what it needs to be fixed. Plus if that's burnt, you may need to fill it in (logo is raised). Like smokey said, some silver testors, or if you want to make sure you get the shinyness, use something by rustoleum, like this:
http://rustoleum.com/CBGProduct.asp?pid=114

For gold/silver leaf you need to apply a bonding agent. It is what holds the leaf to the surface. then burnish (rub) it with a soft cloth. Plastic or metal surface, it should not make a difference. I think the silver leaf on the apron is a good idea. Might have to try that out myself.

I used a chrome paint pen. Really came out well. Easy to test underneath to see if it will match for you.

I'll check when I get home tonight and report back. I remember doing some research to make sure I got something that looked as close to chrome as I could...

Update: This is what I have and used:

http://www.krylon.com/products/short_cuts_hobbycraft_paint_pens/

#SCP902

No problem. It's not perfect but I ended up covering the whole logo FWIW. It looked pretty decent though.

Thanks for the heads-up Nutty! I have a few scratches on my DE SW apron and that will do nicely!!

I also used a chrome/silver paint pen on the DE logo on my LW3 and it came out fantastic.