I have this local gameshop that sells used games they're so nice that they polished my games I bring in for free (of course I don't abuse their kindness). They have this really high-tech machine that polishes it and works perfectly. It even does wonders for CDs and DVDs (PS1&PS2 games etc.).
If you have a local used game shop maybe you can ask them to do that for your game? If they don't do for free then maybe ask to pay for a small fee?