A Circle

As far as the crown jewels are concerned the index does not help us find the secret location but more leads us in a never ending circle. But it does refer us to line 130 in the poem where Shade states "I never bounced a ball or swung a bat." I went back to Kinbotes commentary on the line where Kinbote states a false continuation of the line "As children playing in a castle find in some old closet full of toys, behind the animals and masks, a sliding door [four words heavily crossed out] a secret corridor." This makes it clear that the crown jewels have something to do with the princes discovery of the secret passage. Also I can not remember where in my notes I wrote, but Kinbote wrote that the secret passage leads outside Zembla which leads me to think it has something to do with the Russians and Taynik (which never gives us much of a def. besides a secret place but I believe that the location is contained in the "four words heavily crossed out").              
The title Pale Fire is some what of an oxymoron which seems to be the theme of the poem since there is so many contained in it. line 131-132 has one of the most important oxymorons which helps in the discovery of Shades killer. "I was the shadow of the waxing slain by feigned remoteness in the windowpane." Feigned remoteness is the oxymoron that should tell us the killer which I am guessing the reflection was in the windowpane but instead it leads us in circles. This is just like Kinbotes added line 1000 which is line one "I was the shadow of the waxing slain" Waxing refering to the bird that was killed. The third to last line which states "A man, unheedful of the butterfly-" (butterfly being Vennessa which I believe to be Sybil or maybe Hazel im just not sure, if we go back to line993. So all this confusion leads me to think that there was no killer but a Suicide. But....

If we go to a few more lines

177-181 "And finally there was the sleepless night when i decided to explore and fight the foul, the inadmissible abyss, Devoting all my twisted life to this one task. Today I'm sixty-one.Waxwings are berry-picking. A cicada sings."

726-727 "But Doctor, I was dead! He smiled. "Not quite: just half a shade," he said."

756 "Then, one day, I came across what seemed a twin display."

There was a day when someone the waxwing was sixty-one when a twin was born one being shade.
I believe that shade committed suicide like the dear Venessa or Hazel, but only half or one twin did the dead, which left half or the other twin to explain the unfinished poem.