Thanks for the offers of help. I think my disk is in good condition (so don't need a new one) and at the moment I would prefer not to post it as I don't have great confidence in it making the journey on one piece.
I am really surprised that no digital copy seems to be available. I have a Cowon MP3 player/recorder which can record from either an amp or directly from a turntable so will ask around my local friends to see who, if anyone, still has a functioning turntable.