from a strange mythical era when esarai made bad models
It's not actually bad. Quite detailed even for today. Too bad that most of the details are just city-like clusters of boxes. Everything is disappearing under badly applied tilemapping. Anyway Amaterasu still can be used alongside with newer and better models.
While the tile mapping certain could have been done with more "finesse", it's one of Esarai's earlier models. It's also huge.
You'd probably need multiple 2048x2048 textures to not have them look BIG PIXELS up close (which should be done - the Amaterasu is a joy to fly around, and even
through, given the way the hull is designed).
I think its fine.