In article ,
wrote:

I assume pianos are built to different designs without knowing how to
build one.

You picked an unfortunate example. Grand pianos reached the zenith of their
design 100 years ago. Since that time, there have been almost no changes
that could be fairly described as important. Indeed, a minor change in the
way the strings are coupled to the bridge was the basis for an entirely new
piano company in Australia. One could swap the entire work force of 2
different piano companies, and manufacturing would resume with scarcely a
missed beat.

100 years ago one could buy an American Steinway (the "zenith" to which
you refer), or a piano with a Viennese action, or a straight-strung
Erard with under-dampers.

Perhaps you are unaware of the piano-copying cottage industry. With
enough money and enough lead time, one can purchase a copy or a
restoration of a piano built in the 19th or 18th centuries.

Unfortunate, indeed.

Stephen