There was a “Golden Era” of piano manufacturing (between about 1920 to 1950) and some pianos from this era are highly regarded. These instruments are often well worth investing the effort of a complete rebuild. This especially includes Steinway instruments, though Mason & Hamlin, Baldwin, Knabe, Beckstein and Chickering are also notable instruments. Rebuilding involves replacing the strings, hammers, finish, tuning pin-block and occasionally even the sound board, of an older instrument to restore it to its original condition. A well-rebuilt instrument usually cannot be told from a new one without very careful examination. Rebuilt instruments are often even better than the original piano as the seasoning of the woods and slight improvements to the original stringing designs can bring out the most desirable qualities of the instrument.  The value of an instrument must be carefully considered before beginning a rebuilding project as rebuilding can exceed the value of the instrument or the replacment cost of a newer one.​