Discovering old wood flooring

I've always wondered what was underneath the 1/4" painted plywood on the attic landing.  I ripped it up a few weeks ago and discovered original hardwood tounge and groove flooring.  The wood appears to be of less quality than the rest of the house, probably since this was on the attic staircase.  It was pretty dirty and had the original stain on it.  Here is a shot of it after doing some sanding.

The floor appears to be oak and the nosing (painted in picture still) appears to be fir or pine.  I used a random orbit sander and 60 grit paper to sand the floor and nosing to bare wood.  I set all old nails and drove some new nails.  After everything was cleaned, I proceeded to lay down my coats of poly.  I used Varethane semigloss oil based poly.  It gives the wood an amber finish.  Here is a shot of half of the floor bare and half with one coat of poly. All of the stairs in the house had been painted with a porch and floor paint in a maroon color. Another ongoing project of mine is taking the main staircase back to the wood treads and white risers (also original).  Lucky for me, the prior owners decided to lay plywood over this floor and painted it.

I love the rustic look of the floor and can only hope that this will last another century.  Our house is built as a colonial revival/arts and crafts style. Most of the woodwork is painted (as it was since it's inception) but the floors are all oak strip.  I really enjoy bringing back original features to the house.