This Nexus mods page offers multiple packages to be downloaded. These individual packs were only used to upload the content, their functionality is otherwise irrelevant.
Each package contains numerous Gallery items, with their files grouped, so in case you want to install a specific Gallery item only, you can do so.
Each package also comes with a TXT file, with basic information about each item (eg. required DLC packs, notes).
Part 1 of this mod can be found here: https://www.nexusmods.com/thesims4/mods/1662
Installation and usage:
Download the package, and unpack the content from the relevant subdirectories to the 'My Documents\Electronic Arts\The Sims 4\Tray' directory. Access the installed content from the Gallery.
DLC pack usage:
Each item is more-or-less thematic, and they use as few DLC packs as possible, and no Custom Content, while retaining full functionality,theme, and the overall feeling.
Lots that have notes about their development location may not require that aprticular DLC pack, that contains that certain world, and can be placed anywhere else.
'Moveobjects' cheat:
During the placement of some lots, the game may warn you about the 'moveobjects' cheat being used during development.
That is not true. All of my lots are totally legit, fully functional buildings.
Gallery content by pack:
* Pack I:
- Ancient Moocaster Castle
- Johnson household: inspired by the GTA San Andreas protagonist and his family
- Lord Volpe household: inspired by Lord Volpe's story, and a reference to him in the Werewolves DLC by Kristopher Volkov
- Marchipelen household: Romanichal family
- Romanov household: inspired by the Romanov Dynasty, the former Russian royal family