The Adventure of the Three Garridebs

According to Dr. Watson's opening narration, this story is set at "the latter end of June, 1902... the same month that Holmes refused a knighthood for services which may perhaps someday be described." This is a parallel to the knighthood of Arthur Conan Doyle around the same time.
Holmes receives a letter from a Nathan Garrideb of 136 Little Ryder Street, asking for help in a most peculiar quest. He is looking for another man with his unusual surname, for it will mean a $5 million inheritance for him. He has been approached by another man, John Garrideb of Kansas, who says that he needs to find others with the same last name.