Al Lewin's Stella is suffering from over-ambitious use of oil.
There is no way the comb and dampers should be covered in oil.  This
is preventing the comb from ringing.  It sounds as though even the
mechanics are covered in the dreaded stuff.  This box needs a total
cleaning and then a light relubrication on the bearings with just the
smallest amount of light oil.

Nicholas Simons, GB