1. The Latin Quarter, in particular around the old Place Saint-Michel (not the Place du Pont-Saint-Michel, which is where the modern Place Saint-Michel is located)
2. The area between Saint-Merry and the Hotel de Ville
3. The area surrounding Les Halles (Not as important; I already have a blurry closeup of this, probably from the same map)
4. The Boulevard des Invalides and the rough triangle formed to the right of it on the map
If someone has those from a different map, it's fine too, as long as the map is from before Haussmann went and changed everything around. 1820s-1840s is best.