The heyday of piano manufacturing in the U.S. ran approximately from the 1920’s through the 1950’s. Hundreds of thousands of pianos were built by manufacturers who are no longer in business.
Many of these pianos were of good quality and can continue to make beautiful music for up to 100 years.
If there has been water damage to the instrument that can be fatal but otherwise you may be able to continue enjoying your piano for years to come with regular maintenance and tuning.
During the 1950’s many manufacturers started using plastic parts or elbows in the actions of spinet and consoles (smaller that a full upright). With the passage of time, these plastic parts degrade and start breaking. It is possible to replace these and revive the piano so it will become playable again.