Simon Peter and the Cheshire Cat: Was Peter in the "Original" Gospel of John?

Cheshire Cat fading to smile

... All right,' said the Cat; and this time it vanished quite slowly, beginning with the end of the tail, and ending with the grin, which remained some time after the rest of it had gone.

`Well! I've often seen a cat without a grin,' thought Alice; `but a grin without a cat! It's the most curious thing I ever saw in my life!'

The Cheshire Cat in Lewis Carroll's Alice in Wonderland has the remarkable ability to appear and disappear at will. At one moment he is conversing pleasantly, imparting information Alice already knows, and the next vanishing from sight. Simon Peter performs this very trick before our eyes in the Gospel of John.

Interpolations in the Witnesses, Josephus Antiquities

I used to play the same game that christian scholars like to play, called find the part of the story Josephus wrote, when examining the passages containing information about the early Christians and the famous stories that Josephus might have been aware of. But I don't play that game anymore, because I know the answer.

Interpolations in the Witnesses, Justin Apology 1.26

Nothing is more annoying than having to deal with the interpolations of witnesses from pious scribes. These interpolations are in fact dangerous land mines left for scholars when undetected. And worse they are, even when found, often left unmarked, dare I say for political reasons, because they can be convenient obstacles  for defending the modern orthodox opinion, helping against criticisms - its saves the main body of ecclesiastical scholars from having to think hard about underlying premises of the message. But for the scholar who isn't worried about the theological conventions, looking at the text scientifically to uncover and understand the strands and threads that make up the development of Christianity, it is nothing but a hindrance to the truth. 

My tipping point for me was not with the at least somewhat understood interpolations in Josephus, but with