Maury,  Be careful opening Pandora's box.  The one thing that
I can safely say about Orchestrelles is that there are almost as
many differences between Orchestrelles as there are Orchestrelles.
There are a few things I would say that may or may not help you
track down the problem:

1. Does the cipher happen during manual play only or does it happen
during automatic play?  If it happens during automatic play, then
your problem wouldn't be with the keyboard but perhaps with the
primary or secondary valves associated with the note.

2. Is the cipher present on all ranks?  If you pull out only one stop
is it there for all the different choices?

3. What model is the Orchestrelle?  Is it a pressure or a vacuum
model?  The different model makes a big difference on how to track down
a problem.  (The quickest way to tell if it's pressure or vacuum is if
it has a glass door in the roll box.)

If the problem is only with the manual play, I would suspect the
keyboard or touch box.  If it happens all the time, then I would
suspect the valves.  If it is only on one rank, then I would suspect
the "motor" for the one note on the rank.  If it's a suction model,
it could be the actuator in the back (for all notes as well as the
valves).

If that helps, then great, I'd be happy to help with more specific
questions but I'd need more information to try.

Eli Shahar