Hi All,  I don't have time to go into detail like Craig Brougher
did but I want to echo his comments about stretching pouch leather.

It's hard to say exactly how far the leather will return to its
original position after being stretched, but it will return.
Also, picture, if you will, what is happening to the membranes
(or cell walls) themselves.  While a membrane does have a certain
amount of elasticity, it can only stretch so far before it is
permanently compromised to the point where it will leak.  The
leakage may be microscopic, but it will be there.

Also, picture in your mind what is happening when that glass marble
pushes that soft leather into the pouch chamber.

My recommendation: Dish the pouch while gluing it in place!

Musically,

John A. Tuttle