I have an Edgley Heritage Anglo that I am working on.  This concertina has a B6 reed (very small - 1975.5 Hz) which refuses to sound when in the closed concertina.  It sounds on the bench and when in the reed pan, but once I close up the instrument, it will not.  The opposing F#6 does sound.  I have checked for leaks even though I would expect this small reed to sound with very little pressure difference.  It does not have a valve, however, I did add one to the F#6 as an experiment.  I would app