There are gaps in between and edges are dark. Not sure if that can be repaired. Previous color was a dark stain so the edges may be dark due to that. Also, previous repairrepairs were made using red oak and that would have to be replaced.

I would replace with real wood. If you can afford it it's best to refinish them all at the same time. It will mean a matching finish, plus it will revitalize those old floors.

We have old wood floors throughout our entire downstairs. We had to replace a lot of boards because of a previous roof leak that damaged them in kitchen and formal rooms. We did it as part of the kitchen remodel and refininshed everything together at the end of the project. The woodfloor people were great. They spliced in new white oak to fix the damage and used woodfiller all over to fill the gaps between the boards, scratches and knicks. When all the sanding and refininshing was done, the floors looked awesome. A good wood floor professional can definately give you a wood kitchen floor, match your old floors and bring everything together. But I think for sure you would need to take the red oak boards up and replace them with white oak because the different species of oak will take the stain differently. Good luck!

Eli Mo , refinishing all at one time would be ideal. Make sure that not only the stain is matched but also the wood grade, grain, and plank lengths.

Thanks everyone! We decided on adding the wood. So excited! I will update once they are installed.

Please make sure the old floors have enough meat on them (wood above the tongue needs to be 3mm or thicker) to get you through a full sand and refinish. At 70 years old and a bad DIY level finish/repair these floors are very close to their last days.

You may want to have the professionals give you their opinion as to how many more sand/refinishes they have on them. If this is their last, I would hate for you to go through all the trouble of matching only to have an entire wood floor that will never see another sand/refinish. And to get them all even/seamless, they have to sand down the new ones to the same thickness as the old...meaning the new one's may have a very short life-span regardless of how old they are.

Just something to be aware of. If it were my floor and I this was the last sand/refinish possible, I would throw in some nice tile or some nice vinyl (in a stone or tile look) and leave everything age naturally....without wasting good wood trying to match 'bad' (a floor that only has 20 years left of life).