You are an absolute star!!!!
I have followed your advice, and the lcd is nearly good as new!!!
There is still a tiny bit near the bottom of the screen, but I am hoping that this will go away in time. If it doesn't I will open it up again and repeat the hair drying procedure. If by chance this is actually a water mark, would it be sensible to clean this with a solvent, and if so, what would you think is best?
Once again, thank you so much for your help, it has been invaluable, and I want you to be fully aware of what a great service you have provided to me. Thank you!
Kindest regards
Michael