I like the idea of a ringed station made of starship shells. But I wonder if instead of making hollow starships and then having to deal with all the engines and fuel tanks when converting to a ring segment, perhaps it would be possible to make a tubular section which fits over the outside of starship like a sleeve? I suppose it would need cutouts for the flaps since that starship would ideally be reusable, and it would need to be two halves since there is no way to slide it off if there are flaps there. But IDK maybe it could work!