Those factories have held up quite well to the elements, i'd say spend a few thousand on replacing the windows and a bit of inside work, i recon them places would be able to run again just fine. but i suspect the big wigs will step in soon and they will be torn down instead
These building are full of Asbestos and will take a LOT of Money to put back into service. Unless they can be added to the National Historic list so the government can put money into them, they will sit like this for a long time. The GE Plant in Rome is the same.