This is a novelty map of Norwalk produced by Landis & Hughes in 1899. It's not the most detailed map, but it has great images of particular buildings, many of which still exist.
To zoom in, check out the original at the Library of Congress.
This map is mostly about businesses in downtown areas, so I don't know how much accuracy we should expect for the placement of houses on Roton Hill. I think it's interesting that it shows an actual lake at the corner of Keeler and Flax Hill. That area today has power lines running through it, but it's still a wetland.