yes so scale them, if you scale a selection of vertices in one direction then they will all line up when the small red square lines up over the blue one in the middle. So in you pic above grab the red handle and scale it in until it shits over the middle handle. Those verts will be lined up and you can then mirror without having to much cleanup afterwards.
Alan
Technical Director - Framestore
Currently working on: Your Highness
IMDB