Nowhere. Why?
Because:
1) the Kallinikos name signed to the letters was done by Simonides and as such in that instance they are one and the same
2) Simonides didn't have jack squat to do with Sinaiticus AT ALL
It is unclear if they even knew of the notes.
Not surprising given Simonides didn't know anything at all about the manuscript other than what Tischendorf had said.
Afaik, they are not even mentioned by anybody until around 1860, so that is the operative terminus ante quem.
So are you going to be consistent and go with, "Since nobody said anything about it, it therefore must not have existed" - and presumably tell the rest of us that Tischendorf "likely" put them there? I mean, you're so unfair with him otherwise with your allegations, what's one more?
Or will you for once use your brain and say, "just because something isn't mentioned doesn't mean it didn't exist"?
You can continue to avoid posts where you've been exposed as hiding information yourself, but we have no obligation to simply let your sleazy tactics pass by the wayside.
What are you hoping? That in a few days this will all go away?