You mean that nothing older than that scroll is still in existence.
There are no extant records of the flood of 2350 B C, and you will find very few extant writing of only 2,000 years ago, let alone 4,500 years.
As badly fragmented as the clay tablets to the Eridu Genesis is, it is the earliest Sumerian source to the flood, with Ziusudra as its hero.
The Eridu Genesis is written in Sumerian during the 3rd dynasty of Ur (c 2112 - c 2004 BCE), but Eridu Genesis is based on the older oral tradition.
The 3rd dynasty of Ur is often referred to as the “Sumerian Renaissance”, because of art and literature were flourishing in the late Sumerian civilisation.
And Ziusudra is mentioned in a Sumerian poem of Gilgamesh, called the Death of Gilgames (or Bilgames), where the Gilgames met Ziusudra, as well as the Flood being alluded to.
Ziusudra is also mentioned in even earlier text than the Eridu Genesis, known as The Instructions of Shuruppak. Shuruppak is historically the name of Sumerian citystate, as well as the name of its king, and judging by the Instructions, Ziusudra was Shuruppak’s son.
This father and son relationship, also appeared in one of the versions of the Sumerian King List (WB-62, a recession of the earlier king list).
Anyway, back to Eridu Genesis. What does survive concerning the flood is about the Ziusudra sacrificing to the 4 great gods of Sumer, after leaving the vessel, which is basically very similar to the one in the Old Babylonian Epic of Atrahasis (17th century BCE), and in the 11st tablet of the Epic of Gilgamesh (from the 7th century BCE, Assyrian Library of Nineveh).
Based on the similarities between Ziusudra and Atrahasis, and between Ziusudra-Atrahasis to Utnapishtim, we can assume they are the same person, with Ziusudra being the original character.
You don’t seem to understand the popularity of Sumerian culture and literature, especially the Epic of Gilgamesh, because a fragment of the tablets were found in Megiddo, during the late Bronze Age (dated to about mid-2nd millennium BCE). Tablets of Gilgamesh have also been found in the Hittite capital Hattusa, in Ugarit (northwest Syria), and in Amarna, Egypt (Akhenaten’s capital), all dated to around the same times as the Megiddo tablet fragments.
Most scholars think due to the popularity of Babylonian myths, they were known to the 1st millennium Israelites during the two kingdoms. It is obvious that Israelites writers adopted and adapted the Utnapishtim story, modified for Jewish audience/readers.
Sorry, but all Sumerian, Babylonian and Assyrian surviving literature are earlier than the oldest Old Testament texts.
Moses definitely didn’t write the Torah, because if he did live, he would have predated the Hebrew alphabets. But there are no historicity to Moses, to the Exodus, nor are there any evidences that Joshua ever invaded Canaan.
And before the invention of the alphabets, the Bronze Age Levant, like those in Mesopotamia, were writing their own versions of cuneiform. Cuneiform were invented by the mid-4th millennium BCE, Uruk, a city that Genesis 10 don’t exist until Nimrod built it. But the archaeology demonstrated that Uruk was the largest city in the world at that time.
It just show how little Iron Age Jews about ancient Mesopotamia.
