So basically i cant get to that book in Signus's house. The dwarven box thing is sealed closed with a dead septimus and the sweet book inside. (don't know if this means i can't continue with the main quest cause i'm not up to this bit yet, but i still did get the elder scroll).

Pretty sure it happened because of how i did it. Here's my story:
I went wandering about out behind the mage college and stumbled across his little snow cave thing before i was directed to find it for the main quest.
Sounded epic so i did it straight away and got up going inside the cube. Just before taking the book realised it was way to good a quest to just be hidden away, so i got on the google.
Found out it was part of the main story, so i decided to leave the book for later when i am up to it. [didn't want the quests getting out of order and the game to bug out like i have read it does from time to time. the irony]
But yeah i took that blood extractor from septimus's cold dead body (for some reason i like keeping those things) and got on my way.
When i tried to store the extractor it was apparently still a quest item, so i took it back to find a closed cube and no septimus.

Also, the quest info is a bit odd. It's directing me to go grab the book, but the description above of what the quest is all about is telling me i still need to give septimus the blood.

Finger's crossed you can fix it, i am balls deep in this game (80hrs i think) and not super keen to do it again any time soon. Oh and also so nobody else gets done in by it.

And i am on xbox... Pretty ready for next patch without dragons pooping the bed.