Can anybody guess what these other MSs could be? Wait...is that a DOM? There's no way the EXA-DB would have data from other timelines unless...wait.
>Rose of Hermes blueprints
>GA (Gundam EXVS)
Is it possible that they are just the same thing?
> Winter Palace
I think you mean Black History. The Winter Palace was it's physical location, but it was used for several purposes and not just storing the Black History. It was arguably not even it's most important function, since keeping the vast majority of their population alive in stasis is presumably more important to most people than historical records, regardless of how apocalyptic.
I'd say the scenes of G, Wing and X in Turn-A's black history (and Corin's memory) were just that initially too. They grew to be more over time, but I think it was just the production team putting them in for references and fun at the time.