My mother named 2 trustees in her will-one was a friend, the…

My mother named 2 trustees in her will-one was a friend, the other her Solicitor. Today I located the son of one of these trustees(the friend) and have found out that his father passed away 13 years ago. The son gave me the exact date of his father's passing. The I found out from the Law Society that the other trustee(the lawyer) has retired from practising law and he passed his wills to another lawyer to keep on file. I am unable to locate this lawyer who was named as a trustee by name on a white pages directory search. The law society can't give me his home tel # XXXXX they have on file from his retirement date 4 years ago. My mother's will was made in 1968. Here are my questions:

-If the lawyer named in the will as a trustee has retired from practising law is he still (as the human being named on the will)the legal trustee of my mother's estate? If not, then I presume I don't need to find out if he is still living. In that case, do I need a letter from the Law Society stating his retirement so that I can apply to administer the estate/will? The will specifically states that "I appoint my Solicitor ___________ (then states this man's name). If he is still considered to legally be the trustee of the estate, and I find out that he has passed away, what proof of death would I need to obtain for him, as well as for the other trustee('friend' mentionned above) who I know has passed away, in order to apply to the courts to be the administrator of the estate/will?

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