Solid Hardwood, Engineered and Laminate Flooring - Hard Wood Floor care

I recently moved into an old 1923 house, which I adore. However one of the bonus' of the house, was also a setback. The hardwood floors. They are in fairly good condition however, small pieces have almost what look to be like dry spots'. As if they need to be oiled. The spots' are lighter as if the moisture has been sapped from them, and they are near where the old floor heater was originally. I would hate to have to tear them up. Being young still. I dont have much money to put into them. I wanted to know if there is any item' or mixture someone suggests to put on the floor's to bring back some of their luster and shine without having to resand and redo all of the varnish for a few spots.

Thanks :)
-Talia