The King James Bible was written by the Church of England, a denomination, and was derived from the Catholic Bible, another denomination.
Therefore, claiming all denominations have fallen away from the Word undermines your source of Scripture, thus nullifying any references to Scripture that support your argument. Thus, if you want to claim all denominations have fallen away you will have to do so without any Bible created by said denominations but your word only.
On the other hand, if you want to claim that the Word was intact up until the Church of England you will have to accept their theology up to the point that they were fallen away, such as veneration of the Virgin Mary.
An argument cannot stand if it pretends to disqualify a source on which it depends.
Just because someone translates the original scripture, it does not mean they are saved or that they even understand the Word of God. God gives understanding to those who obey and humble themselves. See John 14:21, and Luke 10:21.
Many think the Catholics determined what books were to be included in the Bible, because they over the centuries publicly listed the books that they used. There were canons put together and used by people even before the Catholics. Different people gave personal statements about the books, but they were only commenting on the books and letters that the first Christians used from the beginning. They had only acknowledged those books early Christian communities already accepted as scripture.
The Catholic denominations started to introduce heresies in approximately 310 A.D. The Roman Catholic Church, which taught things contrary to the Bible, began with the prayers for the dead and the sign of the Cross. The Catholics continued to bring in many false teachings.
Official canonization of the New Testament scriptures came about because of heresies Gnostics and other sects spread. The first Christians accepted as scripture New Testament teachings by letter and books right from the beginning.
The New Testament teachings were by letter and books right from the beginning. In 1 Timothy 5:18 Paul joins a New Testament scripture (Luke 10:7) to an Old Testament scripture (Deuteronomy 25:4) and calls them both scripture. In addition, we can see in 2 Peter 3:15-16 Peter recognizes what Paul writes as scripture.
2 Peter 3:15 Bear in mind that our Lord’s patience means salvation, just as our dear brother Paul also wrote you with the wisdom that God gave him. He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction.
Again, the believers from the beginning used these books and letters from the start. That is what determined these books as scripture.