When a piano is of historical significance, special guidelines are used during restoration. I approach the piano as though you are a museum curator, and together we devise a "Mission Statement". The primary concerns in conservation are preserving the artifact as a document, and reversibility. Authentic parts and processes must be used, and removal of original finishes and parts is avoided. At the same time, I try to meet the goal of making the piano as playable and usable as it can be, without violating conservation standards.
Below are examples of processes and techniques I employ. Very good musical and cosmetic results can often be achieved in this way. At times, with very significant pianos, preservation "as-is" is the only goal. At other times, the original parts are labeled and put into storage, and reproduction parts are put into use so that the piano may be enjoyed.