Not a letter but a memo, by someone who is involved in the detailed policy and planning of civil disobedience, titled "Memo. In connexion with meeting on Wednesday, July 27th, to discuss possibility of mass ist (sic) down in Central London".

Not by Ralph Schoenman, since it refers to him. The language is not BR's. Perhaps the memo is by Rev. Michael Scott, or by Michael Randle (Secretary of the Committee of 100), or by George Clark.