I’d have to refer you to Blender Market too. There are a bunch of geo-node building generators for example and modular asset packs. None which I have tested though.
Getting one that does any moment in history is a big ask, I don’t think that exists, too much variety. You’d probably have to get separate ones for different styles.
Your best bet might be getting a bunch of asset packs from different time periods and then plugging them apart and plugging them back together to create variations.
