Apparently there are gadgets on sale which, I gather, polish the surface of a blemished CD. I have seen such things advertised (in-flight magazine once, and other publications) but unfortunately I cannot recall the details. The statement was that it takes "ages" but well worth the effort. Cost was about �20. I would worry about liquids or film being a temporary solution, and if you get it working by such methods then, personally, I would immediately (have) burn(ed) a copy of it which then presumably would last well. Incidentally, you may find that the CD can be played (read) on a computer even though not on a domestic CD player and thus it can be copied without attempting repairs. Best of luck.