finding an address

I am currently looking at starting my next dramatic project, a stage adaptation of a movie.

I have been trying to find a useful contact address for the screenwriter, but can only get hold of agencies and i know how they can be about passing on information sometimes. I’m not looking to make millions on this project, just want to take a favourite of mine to my local theatre, maybe the Edinburgh Festival.

Anyone know links for getting hold of artists, writers, celebrities, etc?