Richard: I believe that the Pianodisc piano you are dealing with is form Young Chang. It's my recollection that overly hard knuckles have been a recurrent problem with this instruments. You may have to replace the whole set. At one time, the Pianodisc factory was replacing them immediately upon receiving the instruments from Korea. Check with John Elving, who is on this list, for more current information. Pat Poulson
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