"Sure, there are books of the acts of various kings (government documents) but in those cases, the Biblical writer is actually using a 'reference' for the reader of his day to go check up his facts or read more. But these are not the precursor documents for JEDP theory to the best of my knowledge."
Not those specific documents, no. They became the basis for what would become the Books of Samuel, Kings and later Chronicles. But my point is that since the Solomonic kingship was more like the kingships of other Mesopotamian cultures than it was like the type of kingship Samuel had in mind, if there was a library it almost certainly contained more than just government documents. And it is these other unnamed documents that probably served as the basis for the Pentateuch.
"Most I have read say it was the pentateuch. Now, I would freely grant that this would be somewhat speculative but not entirely out of line either."
That depends on how you want to define "pentateuch" at this point in time. Many people who make this claim still believe it was written by a single author in its entirety long before the kingdom period. As I hope to show later, however, there is lots of internal evidence that casts serious doubt on this hypothesis. On the other hand, both J and E form of the core of the Pentateuch and much of the material that would form D and P later already existed in other documents, so as long as one acknowledges that it was not yet a single coherent work, the Pentateuch did indeed exist at this time.
"But what is fascinating to me, no one examines Melville, Dickens or Michener, to determine what 4 sources they plagiarized."
In their case we have direct historical and physical evidence that they did not create their works from "plagiarized" sources, whereas we have strong literary evidence that the Pentateuch was. However, their works are actually closer to how J and E at least were created than we might think. Granted the story lines these authors created were their own