We own a 1910 craftsman. The floors are original in all but 3 rooms and the hall. There are big gaps between some of the boards, some of them are lifting up, there are huge gashes in some areas, as well as some black spots where I *think* water damaged between the boards. But I am not a flooring expert so I honestly have no idea what I am talking about here Also, in our bedroom ,there is almost an entire corner where it was filled with a yellow wood filler.

I do know that underneath the floor is just the wood boards and then the crawl space. No insulation, no sub floor, nothing. We can sometimes feel a draft coming between the boards.

So I am wondering, as far as resale eventually-would it be better to replace the floors, or refinish the original floors? I honestly dont know how much it would take to repair all that appears to be wrong with the floors but there are some major issues