I long thought the code to understanding when the Torah was written was encoded in the LXX itself.

Deuteronomy (the word prefix means 2 and 2nd of 2. There was only 2 books in the original LXX.)

Exodus (the word prefix is the Greek word for number 6.)

So if, Deuteronomy is book number two of two then what is book number one of two?

That would probably be Numbers. Numbers is book number one.

The LXX originally as the book of Jewish Law that the Egyptians wanted for their library 3rd century BC was the books of Deuteronomy and Numbers Those are books of Law.

Genesis is 5 books that were consolidated into one book, and therefore Exodus is also called book 6.

Leviticus is the conspiracy. Jeremiah 8:8. It’s a book written by the Pharisees after the destruction of Solomon’s Temple.