I found that when I retained the original cork gaskets in the Aeolian
stack, I had little problem with the instrument playing too loud.
When I replaced the cork with closed cell neoprene the instrument
played too loud.  Why, because I believe cork does not seal well and
Aeolian compensated for this.

Closed cell neoprene is great for a foot pumper; keep the cork in your
electrically operated full Duo-Art.

Ian McDonald
Australia