Since it’s solid hardwood, I would keep it and refinish it to coordinate with your cabinet and other finishes.

Original wood flooring is a treat that's hard to find, and the continuity with the rest of your floors would also make the house feel larger. But there isn't enough contrast with your cabinets, so if possible I would have the floors refinished in a slightly lighter color. Are they red oak? There are some good discussions on Houzz about how to avoid unwanted pinks and other undertones when staining red oak floors. What are you planning for the uppers? Some open shelving would look good, especially on either side of the window, and it would help the room look larger and brighter.

Wood floors can last hundreds of years, so I wouldn't consider the age, just the condition. If it's lying flat and extends under the cabinets, keep it!

We are replacing the cabinets with new white ones .. the only issues with this floor is the planks are real narrow . Does that matter ?

I agree you should keep the hardwood flooring. I had the early 1990's flooring in my home refinished with a less glossy finish in a color that worked well with existing wood trim and furnishings, and I am extremely happy with the results. The cost was very reasonable. Be aware you will lose access to the rooms being refinished for several days, plus the fumes will be strong. Meaning you may want to make alternate local lodging arrangements, and just come home to monitor the work.

Please don't pull out hardwood floors that can be refinished and last 150 years.

Keep them. And if you're getting white cabinets, this floor will go with them. Only reason to refinish the floor is if they are worn in spots. Your floor is beautiful. Narrow planks? That's fine. To me, wide planks seem like a porch.

Another vote to keep them. Narrow planks are classic- nothing wrong with that! Consider yourself fortunate to have these floors already in place.
My white oak narrow plank hardwood kitchen floor was refinished a few weeks ago. I wanted the finish to be a bit lighter (as it had yellowed and darkened a bit over the 25 years since the last time it was refinished) and used Bona NaturalSeal and 2 coats of Bona Traffic HD in a matte finish this time; it looks fantastic.

Consider yourself extremely fortunate to have such beautiful, classic floors. We just ripped out a whole house worth of LVP and replaced it with real maple hardwood. A huge and expensive project, not to mention moving all the furniture and vacating the house for two weeks. For me, it was totally worth it as I can‘t abide by faux anything.

Why does it appear the flooring boards are all curling up on the edges? Is this over a slab by chance? Is the floor solid or engineered?

Keep the timeless hardwood.

Millworkman, after we pulled the old cabs out we found that they didn’t put hardwood under the cabinets. The floor is solid and not on a slab.

The pictures do make the floors look like they are cupped . Do you mop or steam those floors?

I mop. I think it’s just the pic.

Still an easy floor to patch even though it doesn't go under the cabinets. The width is still sold, just make sure they match the species.