Most of the information about Dr. Arthur Conan Doyle and his circle of friends in Southsea comes from A Study in Southsea, by Geoffrey Stavert (Milestone Publishers, Portsmouth).
The description of Portsmouth and Southsea in the 1880s comes from Southsea in Old Picture Postcards, by McAvery, and Portsmouth, Then and Now, by A. Triggs.
Major-General Alfred Drayson was Conan Doyle’s chief mentor during his time in Southsea. The Portsmouth Literary and Scientific Society was as I have described it, as was the Bush Hotel and its environs. Unfortunately, Portsmouth sustained heavy damage in two world wars, so most of the areas described in this story are no longer there.
Except for certain members of the Portsmouth Literary and Scientific Society, and Mr. Hill of the Bush Hotel, the characters in this novel are fictitious, as is the Indian state of Rajitpur and the Rajitpur Treasure.
Mr. Dodgson and Dr. Doyle never met. This is an exercise in “what if …?”