Advanced users navigate to %LocalAppData%\IMVU\ (Windows) or ~/Library/Application Support/IMVU/ (Mac). They locate the cached files for a specific old Room ID. By using a third-party 3D model viewer (like Noesis or Blender with an IMVU plugin), they can reconstruct the visual shell of the historical room offline.
This is the most functional aspect of the historical room viewer. Every time you visit a room, your IMVU Classic client downloads the following to your hard drive: imvu historical room viewer work