One thing to keep in mind Matthew is you don't necessarily have to do a perfect job. For this application a decal I reckon is the go, but I have done some touch ups where I try to blend in with the scenery than try to get the exact line width or even colour. I find I can fool the eye from an acceptable distance and at the very least from the playing distance, that's good for me. My work can look a bit ordinary if I stick my nose hard up against the playfield surface but that's not how I normally look at a playfield. The pros like Gav will probably disagree but on a busy pf like space invaders I found it hard to find some of my work just because your eyes just don't focus on specifics a lot of the time. I think on plainer artwork you have to be more careful. So don't be necessarily put off with the dots as near enough may be good enough from the normal viewing angle.

Thanks very much for your reply  

I am hoping somebody might be able to help me out with the decal ( ), but I would also consider trying to touch-up the worn area if I knew what kind of paint and brushes would be required to do it and where to buy the paint and brushes from?  

Cheers,
Matthew