I got a dilemma about this elder scroll and wondering since I have both got the quest for the blades and the dawnguard to get it who do I turn it in first or does it matter? I read in the book if you do it for the main storyline the blades you can still get the elder scroll dragon from winterhold but how? buy it or what?

You're gonna have to reword that. Too confusing. The Blades have nothing to do with the Elder Scrolls.

It doesn't matter who you turn it into first.