Bob; The first thing that comes to mind is the receptacle for the lid pin on the treble inside rim. The second thing that comes to mind, given your desrciption of the buzz, are the locking nuts on the pedal rods.(Like Jim C., don't ask me how I know about these buzzing!) If it is one of these two things causing your problem, my money goes on the lock nuts. Jim Bryant (FL)
This PTG archive page provided courtesy of Moy Piano Service, LLC