Jeff, the reason the report was sent to W.H. Smith was because Sir Charles Warren, in his evidence to Curtis Bennett, stated, "I have spoken to the Secretary of State and the First Lord of the Treasury as to Mr Evans' financial position." The First Lord of the Treasury was W.H. Smith.
There is a letter on the file, on 10 Downing Street notepaper, from a Mr. Pattisson, who I believe to have been W.H. Smith's private secretary, to John Satterfield Saunders, who was Henry Matthew's private secretary, dated 16 July 1888, which says:
Mr Smith has read the report relating to Mr Evans of the Metropolitan Police Office and now returns it. He will be obliged if you will kindly thank Mr Matthews for sending it to him.