A few things come to mind.
1. Inspect the hell out of this property, hire a contractor or someone else who actually does work to be your contractor rather then a "home inspector" Matter of fact hire two or three of them. Become an expert in 1800's masonry building techniques.
2. Historical Building? This building feels ripe for other folks telling you what you are allowed to do with it. Because "preserving the historical character" Just means its gonna cost a hell of a lot of money to do normal things to the house. I'd start with calling the building department and investigating from there.
3. Water, how does the house look in terms of water management. Stuff is gonna be unlevel which is fine. But id be looking for big cracks, bad grades, crumbling mortar, poor draining. Visit the house in the rain, the heavier the better. Walk around the outside, get yourself soaked this is time well spent. Stand in the basement during a storm and see what happens.
4. Yes would cost a fortune to heat and cool. Yes you can insulate a house but it has to be done correctly or you can really damage the masonry walls. Also see point number 2, it might be easy to do in a normal home but absolutely forbidden in this one due to its age. The type of heating you use is irreverent if it all just seeps out the walls and roof.
5. Lead/Asbestous/bogeyman - yeah its gonna have this. Lots of houses do its not the end of the world just be prepared.
I am not down on old buildings, I actually like them over new builds way the hell out in the boring burbs. I think the quote is something like "An old house is not something that we own, its something that we do" Good luck and let us know how it turns out.
