You might try an old trick from way back when. A good abrasive toothpaste can work wonders. Make sure you polish in a back and forth movement, avoid any circular movement it can throw the laser off. Some folks have used automotive polishing compound as well but not guarantees from the dog.
The important thing if I remember is never use a circular motion, just back and forth from center to edge. Take you time don't get too aggressive. It works more than you would expect. Try to use a full size ROM to read the disk, laptop optical drives are so-so.
If you can get it to read dump the entire contents onto a hard drive. You can then move it to a USB stick and no longer be dependant on optical media unless you want to be.