Homebrew PCBs

I decided to make another motherboard for my TVT.  The first one involved
some trial and error and it showed, esp. some of the traces where my first
attempt at etching managed to get under the toner.

 

So I made a new one, but I think I goofed and didn't put enough vinegar in..
the result is there are just a few small, mostly faded patches of copper
lefer where I don't want them.  I've tested traces and there is a *little*
bit of conductivity where there shouldn't be, so I need to get rid of these.
Is there a way to do it without wrecking the board?  I was thinking maybe
dremel but I'm afraid of pitting or hitting one of the traces.

 

On the subject of cutting, I bought a carbide tipped laminate cutter.  Works
amazingly well!