There's more info on the recently leaked 1997 build of OOT. It apparently contains all the text of the game up to that point and there a some interesting differences in the story compared to the final game like Navi being rescued in the first dungeon and the game starting on a fairy ceremony.
https://tcrf.net/Proto:The_Legend_of_Zelda:_Ocarina_of_Time/Late_1997_Overdump/Scenario
CC: @coolboymew
@coolboymew I'm hoping for some early character models. That picture on the TCRF page is early concept art. Navi was originally supposed to look like the fairies from ALTTP, Sheik looked more middle eastern, and Gannondorf appears to be more Caucasian.
Also, there is unused text in the final game that suggests backward time travel. Maybe there's more text relating to this in this 1997 build.