Under the "Fun with CDs" category: Get a yellow sticky note and scissors. Cut a very sharp angle from the note where the glue is, say
1/4" down to a point. Attach to the (duh!) none label side with the point near the center just after where the pits begin. Use a disc you know well.
You'll find out how much error correction can do. Amazing. Please post results. BTW, dealers hate this stuff.