Maybe there are two doors.
One for the pull and one for the push.
Just like the valves on the reeds.

From the description of it being like one of those cat doors, it sounds like it swings open in both directions, one way on the push and the other on the pull. That's the picture I get anyway.

-David

the trapdoor moves to both sides of the partition, so when you pull you suck the door into the bellows, and when you push, you blow it towards the reeds, that is probably the reason why the bellowbox on the treble side is deeper. The little weight attached, makes the trapdoor fall back at a certain point, when it falls it falls back through to the other side, because of the weight the door keeps swinging back and forth.
it`s realy best compared to a catdoor, it moves to both sides through the door......

Man i have a hard time trying to explain this

as for the sound...you all must have heard a hammond organ with a Lesley speakerbox attached.
it makes soundwaves by covering the actual speaker at a certain pase, it`s the same effect: sound - no sound.

When i meet the guy with the instrument il will ask some more questions, Ron will be there also, so he can help me

to be continued

Wow, that is the weirdest accordion contraption I have ever heard of! It is hard to imagine what it sounds like.

Thanks for finding out. It is a very weird contraption.

That`s OK Phil, i had fun doing it.

Hey Will,

Any chances of some pics?.

Unless. of course, it's a "good" Aussie joke .

Claude.

FYIW ..

I've seen the same thing some some older Italian
piano accordions.

I remember Alfonso Baldoni removing one of those
contraptions as an order of business when he had
one of my old accordions open.

(I don't think he liked it in the piano accordion )

--Big