Hello, I have a Danemann player piano with APPA Action.  The action
is not in very good condition and must be rebuilt.  Now I'm in
progress with the pneumatics and I need some information about the
valve unit.  I'm not sure if I can open them without damage, and
what then comes out.

I have read that someone here rebuilt an APPA action in the past.
If anyone has some information about this action please let me know.
I'm thankful for all I can get.

Best regards from Germany,
Michael Benz