If you don't want to spend major $$$, then just cover it w/carpeting, or something that won't further damage the floors. (I'd stay away from anything that's glued down or requires a Lauan, or something, because it will make an eventual finishing job that much harder.)
FWIW, floors like this, that are refinished, have a LOT of character in them. The floor is 100+ years old so ASSUMING it can be refinished (which you'll need to find out at some point down the road if you want more 'value' out of the house), will be an interesting conversation piece when refinished. Deal w/the problems of the floor later on. If I was you, which I'm not, but if I were, I'd just cover it.