Hello and thank you for accepting me into this forum. I am going to refinish my hardwood floors. They are between 100 and 120 years old. I just finished the sunroom and the result is spectacular. With the rest of the main floor, though, there are a few challenges. In a remodel done probably in the 1970s, they tore down part of a wall and took a chunk of the floor off. Also, it seems that when the house was built, the space under the wall frame was routed. It was covered by carpet, but when I took it out and discovered it, I filled it with wood filler while I figure out what to do.the floors are 3 1/4 x 12 feet strips, so I can’t just do a normal repair. What can I do to repair this space? Please see video attached.