There’s a lot of inaccuracies that you’ve presented here.
In 1844, while visiting the monastery of St. Catherine, Tischendorf noted several scraps of parchment in a basket that were “mouldered by time.” Upon closer examination, Tischendorf discovered that they contained parts of the Septuagint, the Greek translation of the OT. It is not certain that these folios were originally apart of Sinaiticus, but there may have been worn fragments from Sinaiticus that were included, but there is no evidence to suggest this. Nowhere in Tischendorf’s account does he indicate that the entire uncial (Sinaiticus) was found in this basket; he only makes mention of several folios that contained parts of the LXX. Those folios could have been apart of another uncial, but that is speculative at best.
In 1853, Tischendorf returns to St. Catherine’s for a second time, but finds no add’l manuscripts.
In 1859, under the authority of Czar Alexander II, Tischendorf made a third trip to St. Catherine’s. On this occasion, Tischendorf either gifts (or at least presents) one of his published copies of the Septuagint to the monastery’s custodian. In turn, Tischendorf is shown a copy a codex “wrapped in red cloth”: Sinaiticus.
In its current state, only a very small portion of it’s nearly nine hundred pages are actually damaged. It is plausible that the monks at St. Catherine’s could have restored some of its time worn folios, but Tischendorf nowhere indicates that segments or folios from Sinaiticus were found in a basket. You have not done your due diligence, and are relying heavily on inaccurate information you dug up on the internet. I understand you’d like to discredit Sinaiticus, but at the end of the day, it is a real, historical document, and needs to be treated as such, no matter how much discomfort is causes you.
I nowhere indicated that Vaticanus and Sinaiticus were “better represenatitives” of the original autographs. In fact, what I said was, that when the two documents agree, they “have been found to agree very closely with even earlier papyri which are dated to the beginning of the 3rd century, this demonstrates by recourse to a postulated earlier exemplar from which they descend. 'In English,' so-to-speak, this means that these mss are representative of an even earlier archetype.” As I indicated prior, there are times I disagree with Sinaiticus and/or Vaticanus, but I take each variant on an individual basis. Sometimes Sinaiticus disagrees with Vaticanus, but agrees with the KJ. Sometimes Vaticanus disagrees with Sinaiticus, but agrees with the KJ. Sometimes all three disagree. But where I think the strongest case can be made is when Sinaiticus and Vaticanus both agree (or perhaps even one-or-the-other) in conjunction with other mss in circulation at the time. That is where your argument runs into problems. You can try to (unsuccessfully) discredit Vaticanus, or Sinaiticus, but you can’t discredit the earlier papyri that agree with them, or even the later 5th c. mss such as Ephrami, Alexandrinus, or Washingtonianus that (at points) agree with them, yet disagrees with the KJ.
There are a whole host of documents that are quite a bit older than Vaticanus and Sinaiticus. I can’t list them all out, but to name a few of the prominent ones,
p46 – It contains (86) folios; all from the Pauline literature. It predates Vaticanus and Sinaiticus, and yet agrees with Vaticanus and Sinaiticus in critical places. There are also places it may agree with Vaticanus, and disagree with Sinaiticus (or vice-versa), and there are places it disagrees with both.
p66 – A late 2nd c. (or perhaps early 3rd c.) document that contains (39) folios; all from the Gospel of John. This document predates Vaticanus and Sinaiticus, and yet agrees (and/or disagrees) with them in places. But then again, there are places where all three witnesses agree in contrast to the KJ. p66 is actually a common ancestor to p75, and Vaticanus.
p72 – It contains the Petrine epistles + Jude. It too, in places agrees with Vaticanus, and/or Sinaiticus, and even at times disagrees with both.
p75 – Is a late 3rd c. mss which contains a large portion from the Gospel of John, and the Gospel of Luke. It is closely related to p66, and Vaticanus.
Sinaiticus is often mislabeled as an Alexandrian witness; but this codice aligns more with a Western tradition than it does Alexandrian in John 1:1—
8:38, but elsewhere does follow the Alexandrian tradition. What this means is that throughout the first eight chapters of John, there are witnesses from two different textual streams: Alexandrian (p66, p75, Vaticanus) and Western (Sinaiticus) — all of which are dated to the 2nd to 4th c. So we can deduce that portions of Vaticanus date back to the third, even the second century. But again, each variant has to be examined on an indivudual basis.