Solid Hardwood, Engineered and Laminate Flooring - how do we patch a large section of old hardwood floor

We have a 100 year old house with bird's eye maple floors. The original design had an air vent in the middle of the floor. When this was removed it left a 3 square foot hole in the floor. We've put in a sub-floor that is even with the original. The floor in the kitchen has been too damaged to save so we were going to use some of the wood from there to patch the other floor. It's all 1 1/2" tongue & groove strips. How do we go about doing that without making it look like an obvious patch job?

cut some more of the strips so that you don't have a perfectly square opening anymore - no straight lines. you want your patch strip ends to be staggered, just like everywhere else.