The Great Hiatus

There are few literary enigmas so intriguing as the missing particulars of Conan Doyle's detective between "The Final Problem" and "The Adventure of The Empty House".  Certainly there are clues, like this one:

"I travelled for two years in Tibet, therefore, and amused myself by visiting Lhassa and spending some days with the head Llama. You may have read of the remarkable explorations of a Norwegian named Sigerson, but I am sure that it never occurred to you that you were receiving news of your friend." --The Adventure Of The Empty House, pub: 1903; Sir Arthur Conan Doyle.

In the vaults of the bank at Cox and Co., at Charing Cross, there is a travel-worn, battered tin dispatch-box containing all of John H. Watson's case-notes. It periodically leaves the safe and materializes in the the possession of  investigators and writers of pastiches and parodies. It appeared here for a moment this morning and displaced the content of my usual Sunday sermon. In this extracanonical  vignette, I shall address the problem presented by the excerpt above. Why did the author spell "Llama" with two L's?
                         [Sigerson in conferrence with the Head Llama]

Head Llama:  Mr. Sigerson, antar jeg - eller Mr. Holmes.
.
Sigerson: You presume correctly. But you are not, I take it, the Tibetan Pope.

Llama:  No, his title is spelled with only one L, but we often get our luggage mixed up at airports.

Sigerson: Then please excuse this intrusion. Though, by what mystery it occurred,  I confess myself baffled.

Llama:  Oh, no excuses needed, and no mystery is involved. This meeting is the mischief of our creators.

Sigerson: Beyond the obvious fact that you are a domesticated South American camelid, well-suited to Andean high altitude, therefore comfortable in the Himalayas, I can deduce nothing. How did you become Head Llama in Tibet?

Llama:  Elementary, I am the only llama in Tibet.

Sigerson: But surely you mean creator in singular and not its plural form. 

Llama:  I am here by a caprice of fiction, a simple misspelling on the part of Conan Doyle, who said: "Sometimes a writer must be masterful, and not nervous about details." Conan Doyle is my creator, my sole creator. You, however, were a joint effort.

Sigerson: You cannot mean my chronicler, Doctor Watson. He and I were created by the same author!

Llama:  No, I refer to your physical appearance, and the illustrator for the Strand Magazine, Sidney Paget, who made your face recognizable worldwide. He took advantage of a model that was available at a moment's notice and whose reliability was unimpeachable. Here, permit me to lay the evidence before you. First, consult the hand-mirror you keep in the pocket opposite your magnifying glass.

Sigerson: Yes, there I am.

Llama: Now consider this photograph of Sidney Paget:

 

                                [Sidney Paget, British illustrator of Victorian era. photo, pub. domain]

Sigerson: Good heavens! I am seldom surprised, even less often astonished, but you have succeeded in inducing both reactions in me. Two creators indeed! 

Llama:  Your investigation is completed then?

Sigerson:  Yes, thank you, there is nothing more to be learned here, and I have a long journey ahead.

Llama:  Go in peace.