I tuned a piano today that was built in the 1880′s! The Pierce Piano Atlas puts it at 1883,but the frame mentions a 1885 copyright so I’m guessing the piano was built in the late 1880′s.
The piano was clean,the pin block seemed to be solid,there was no rust on the strings. The action is worn,but workable.
It is fun to see pianos still in use that are so old. This one is a Kimball,five feet tall. The tone is great due to the nice size of the frame. The family that owns the piano has young children,the oldest of which is playing by ear. She is 6 years old,and really enjoys the playing the piano. I think she is looking forward to the time she will be able to take lessons.

Example of 1880's Kimball Piano
This photo is of a piano very similar to the one I tuned. The wood is beautiful and in great shape.