On the left are the major "action components" of a 90 year old grand piano, with their new replacements. As you can see they're virtually identical.

One primary reason for putting a great deal of skill and effort in restoring a piano is that the technology of pianos has not in any significant way evolved since the turn-of-the-century.

In most cases all the components for the properly selected older piano can be readily purchased,and when the work is finished, the piano's owner can enjoy a first-rate musical instrument, an exceptional piece of furniture, and often a very good financial investment.