The super secret scroll probably describes how to get the rinnegan. Orochimaru already experimented on Hashirama cells years prior to Naruto even starting, hence Yamato's age. It's also described how Orochimaru wanted an Uchiha body from the flashbacks when he wanted Itachi but couln't beat him. Which is why he went after Sasuke years after.

Come one, sometimes one's got to use Occhams razor, and everything indicates that this scrolls describes how to get the Rinnegan. Kabuto even said to edo Madara that he and Orichu did research on this and that their "thesis was true".