Can this floor be refinished?

CaptChaos

Hi Everyone:

I'm wrapping up some other renovation projects throughout my house and am trying to decide the best plan of action for some of the floors. About them:

• House is a 1915 rowhouse in NJ just outside New York city
• Floors are thick (I think 3/4 if not more) solid hardwood directly attached to the joists
• There is no subfloor
• My two plans of action are either to try to sand and refinish the existing floor, or to use it as a subfloor and float an engineered floor over it
• The floor is, as you can see, quite banged up. There are some serious dents and scratches, as well as some places where I can only imagine that there were some majors gaps that have been attempted to "filled in" half-heartedly with wood filler by previous owners (just to put carpet over).
• There is one missing floorboard which was filled in with some piece of common lumber, so I will have to try to find a replacement -- any guess on the species of wood?

So my question to you, dear readers, is this too far gone? Should I try to do a test run with a sander since the cost is relatively acceptable, and even if the end result is not sufficient I can still float a new floor on top of it?

Here's what I'm working with...

CaptChaos

One more note. Looks like when they were laying carpet on top, they also screwed down some of the floorboards to the joists. I will probably have to screw these down tightly and consider the filling the holes over the screwheads if I sand down significantly.

Shamus

I'd sand and refinish that floor in a heartbeat.

Replace any boards that are missing, badly cracked or filled in with wood filler and rent a drum sander with several grades of sandpaper.

And I wouldn't use screws, use finish nails and counter sink them then use a dab of wood filler. Make sure your driving them into a floor joist.

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Shamus