Gradually stain area until I can get it to match?

Q: We stripped and sanded our pine floors in our 100+ yr. old cottage. Long ago, the previous owners painted around the large throw rug in middle of room. Eventually it sat for decades under wall to wall carpeting.

I was able to get three sides to blend with center but 4th side is much lighter than middle section of the floor. Do I try to sand this line / area to blend both areas or is it best to try to gradually stain until I can get it to match?

A: I would accept that this is the colour of those particular old boards and stain as normal. Old pine will offer a range of colouration and this is a natural part of aging.