Holes can be plugged with wooden plugs. The floors are old and will not have much life left. I suggest you sand and preserve it with a neutral penetrating oil. When the finish wears away, you can re-oil it and avoid the sanding. That will help extend the life of the floor.

If, you use a polyurethane system, deep scratches and wear will need sanding to be removed. Which will shorten the life of the floor.

Philadelphia should be chalked full with wood restorers. You want to work with pros who deal with restoration rather than the newest kids on the block.

Thank you, G & S and SJ, exactly the type of info I was looking for. I'll put it out there that I'm looking for a restoration specialist who can help preserve my floors.

My floors are in the same age range and if you pull up one of the floor registers you can see how thick the floors are. Mine are over two inches thick and will last for several more centuries. You may be amazed at how beautiful they will look when restored. Mine are fir and most of the boards are at least 18 ft in length. Can't replace that now days.

Thank you, Raye. I'll be lucky if my floors are 1". I think they're more like 3/4", and I'd really like them to last (at least) my lifetime!