How can we get hold of a will 11 years after a person has died?

My Grandfather died about 11 years ago and my mother never saw the will and was too upset to really go into to much effort to track it down. His solicitors based in Cornwall, where he presumably his will would be, had since closed down. Is there a way of tracking it down? We have recently found reference to a great deal of shares ect that he had just before he died but have no idea what happened to them.