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What General_Strike said. Although it depends on what grade stone you get. If you could find something with say a 600 on one side and then something in the '000s on the other I'm sure with some work the 600 side Would take most of it off.
Otherwise you could always see if you can pay someone. If its just putting it back to good enough nick so that you can go back to just maintaining the edge with a steel it might be easier and more economical..
I was thinking of getting a whetstone - the steel is pretty useless for sharpening the smaller knives i have. I wasn't sure if a whetstone would be any good for taking the edge back past the notches, though.