Yes, I observed the gaps between the strips and placed the strips as close as possible so that, when the air chamber is closed, the gaps disappear. When I blow, I realize that air comes out of the places highlighted in the picture below, but not the from the gaps where the strips meet. I initially thought they were from the key pads, but if they were, would not the sound of the reeds come out? I do not know if it would have any effect, but I pressed the key pads with my hand against the holes of the air chamber and the leak did not diminish at all. So, I do not think it’s the keypads either way.
About the strip in the middle, I believe it is unlikely that it is responsible for causing the leak because of its position. If you look closely at the first and second photos from my previous post, you may notice that with both the old gaskets and the current strips, marks have formed, which shows that they are fulfilling this role of “closing” the path (and letting some openings in the way for air to be directed to the reeds). I put a photo to show this “path” (I do not know how to nominate this).
The screws are tightened as far as possible. I suspect that they may not be enough to close the entire air chamber with a thicker strip because they are only four and have to deal with a relatively wide surface. I thought about trying to put a material more like the original or less thick. What do you think? Any indication?
Next picture, the strips more closely.