I have the impression that your hypothesis concerning the identity of CK and JS would become richer and more workable as a thing Nabokovian, if RLS's novel and allegories were less emphasized.
Dear Jansy,
All I can say in my own defense is that I took my clues from Pale Fire. There are many references to the Jekyll and Hyde story in Pale Fire, starting with the name Kinbote. VN's lecture on J&H seems to make reference to PF, too - - for just one example Hyde is described as a tape-worm, a parasite of Jekyll just as Kinbote is described as a botfly, a parasite of Shade.
But you are right. This is only one among other clues that lead me to the multiple-personality solution.
There are for example references to hypnotism, which I have read was "anathema to Freud" but indispensable in the studies of multiple personality - - trilby, autoneurypnological , and John [?] Coates pointing to James Braid* who invented the word "hypnosis" to replace the older and scientifically inappropriate terms mesmerism and magnetism.
There are also references to "The Picture of Dorian Gray" and "The Three Faces of Eve" - - not to mention Alice through the Looking Glass, in which Alice often puzzles over her own identity.
My argument is that other many sets of literary and historical of references in the novel did not seem to me to solve the puzzle, whereas these multiple-personality references , along with the hidden-in-plain-sight references to "strokes" and the brilliant depiction of cerebral stroke as the escape-from-Zembla, and the "G, K, S" [yes, Jerry - - alphabetical, of course] did combine to form a key which fit and turned in the lock.
Carolyn
* Does anyone besides me remember Coates & Braid thread and notions?