You will get many opinions on the questions asked so I'll attempt to give you mine. Welcome to the forum BTW.
I own a Steinway L built in the 1930's. When I bought it, it even came with the original brochure from the 1930's and it belonged to a local concert pianist. The piano is in my opinion in excellent shape with all original components. It performs well for my level of playing. When I looked around I have yet to see a Steinway piano from 50+ years ago that was not rebuilt. I have many questions that I would like to get peoples opinions on:
People usually rebuild when the piano no longer performs or sounds to their expectations. If you're happy with the piano, all is well in the musical universe. That should be the main criteria. That being said, your expectations may change with time and you may decide your instrument could be better. Or maybe not!
1. Do people only rebuild when the parts are too old or don't function anymore or do they rebuild just to make it look brand new?
People rebuild for all the reasons people spend their money for anything else. Sometimes they want something better, sometimes they want bragging rights, sometimes they just want the piano to last another 75 years and they know it won't without rebuilding. Sometimes the piano looks terrible and they figure it should be fixed while the refinishing is being done. There is not always a logic that can be applied. Different parts of the piano deteriorate at different rates. The cast iron plate will outlast the leather action parts by a considerable margin.
Opinions aside, leather, felt and wood parts have a life span. when is something too worn to be playable? That's up to you. Some people can live with lower expectations than others can.
2. Part of #1 has to do with the fact that Steinways are both a musical instrument and touted as an investment. If they are being used as an investment, how would building it enhance its value if the original components work fine? For example if you owned an antique car say BMW whose original parts were all there and worked fine. why would you put a 2005 engine inside the chasis?
If it's not a "musical" instrument any more what is it's real purpose in life. All machines need maintenance so I personally dislike the "If it's not original it's no longer a Steinway" argument. Does any antique car have the original tires, rubber belts, front end parts, glass, lenses, upholstery, oil filters or gas lines. Certainly not. You cannot find an antique car that hasn't had major replacement of all these parts and more and is still worthy of driving. Are the replacement parts for these vehicles of the same quality as the originals. Hopefully not. Metallurgy and materials sciences have improved immensely in just the last 30 years. The parts made today for the antique automobile are usually FAR superior to the parts they replace. Craftsmanship is the only aspect of auto restoration which has not benefited by improved technology. The same things apply to piano restoration. I would not willingly use materials or methods which were original if I had better methods or materails available. This is often the case as most piano designs being built today are circa 1920 or so in thought and execution.
3. When you buy a used Steinway piano, what is it that makes it a Steinway? (case, soundboard, stringblock etc) For example if you do a complete rebuild leaving only the outside case as the original to me its a completely different piano. Some people have said that the older Steinways are still in demand. If you completely re-build it is it an older Steinway or now a newer Steinway?
The thing that makes a Steinway, IMO, is the rim structure which is the foundation upon which the piano is built. S&S and Mason & Hamlin are the premier piano builders in this countries history because they build a good foundation. Many other piano makers have built good foundations for there \pianos as well, they just never got the marketing or market share that these two acquired.
Most of the pianos that come through my shop need to be rebuilt or thrown out. There seems to be some opinion out there that pianos never die. It's not been my experience. To me it's not a question of whether it's original or not. It's a question of is it musical or not.
Registered Piano Technician