I can't help Derry Fishel directly since I've not seen one of these,
but a quick search on the Internet came up with www.deleika.de which
suggests they are relatively modern organs.  The site gives contact
details so I would suggest contacting them to see if they will give
advice.

It is hardly practical to send the organ all the way to Germany and
back when all that is required is a bit if 'inside' knowledge.  I know
that on some early organettes of various makes, it was necessary to
break down glued joints, but this isn't usually too destructive since
they used hide glue; I'm not sure about modern instruments.

The home page of the Deleika web site suggests you can choose the site
language, but I couldn't get it to switch to English, so you might have
to guess a bit if you can't read German.

Good luck,
John Farmer (UK)
Archivist, Musical Box Society of Great Britain