My early pouch is a heart shaped double, and the divider is the back of the pouch front, and the back, of the pouch back. The gusset is made by taking the pattern for the front of the pouch, and making a gusset pattern by duplicating it top to top, and not separating it, but, simply folding it over inside the pouch. The back of the pouch is also the front flap. There is a patch knife sheath between the separate pouches. The pouch is sewn from the outside through both the front, and back, through a thin buckskin seam cover, around the edge of the pouch. This pouch works much like saddle bags when you place it over a small limb, or fence rail. It also is great for carrying the gear for two separate guns. The strap is woven cloth, with leather ends. The pouch closure is a toggle made from a finger bone. Many of the ideas for this pouch came from an old pouch a friend owns, that actually has a shot bag in place of the patch knife sheath.
I hope this is of some help. I know its not easy to visualize from my description.
Hungry Horse