[Harp-L] 1950's 64 Chromonica

[tom cox <tcslim@xxxxxxxxxxx>]

Hi 
I stumbled across a 1950s 64 chromonica in my local antiques shop, bagged it for 25 quid. Its in pretty good shape considering it age. I'm convinced it was once played by Little Walter. (joke)anyway I have cleaned it up and noticed that when the mouth piece slidder etc are off the harp and I play it directly on the comb it plays like a dream, however once i reassemble it, it doesn't respond as it does unassembled. I don't understand this, can anyone explain why this would be?
Also i tried to completely take off the reed plates but noticed once i had taken all the pins out that the comb is in two parts and also there is a screw holding the two plates together. I don't know how to dismantle this and am a bit worried about damaging this old beauty. 
any advice and heads up would be great 
regards Tom