It's always fascinating to see what mysteries people see in the past, and what answers they seek in the process. Thanks for sharing. If there's one thing I'd consider changing is your book title (I'm assuming that you might be playing around with book title ideas here?)
It seems like your book idea is finding the historical origins of the Mesopotamian flood myth. I think it's confusing to potential readers to bring into it the biblical flood myth. We can look at the fact that Gilgamesh predates the OT by centuries - or millennia - depending on how you calculate it, all we want. We can look at how there are similar-sounding turns of phrase in both, etc. What we can't prove is that the biblical writers had access to Gilgamesh, the ability to read it and translate it, and were inclined to adopt its message - either in part or in whole.
I would suggest letting the Mesopotamian research and work stand on its own, because the biblical connections implied in your thread title are quite tenuous.