I ordered a piece of brown pebble grain textured cowhide from Leather Unlimited, 2mm thick, in order to create Bomber Jacket style notebooks. This one was my first finished prototype. It was designed to hold eight inserts comfortably, for the "power notebook" user.
Here, it's loaded with five inserts, one of which is a leather zipper pouch made by Melissa Chao, "To Boldly Fold", Etsy. https://www.etsy.com/shop/ToBoldlyFold?ref=ss_profile
I extended the Bomber Jacket's width in order to accommodate up to eight inserts, so with the five you see, it has a definite hangover which works for some, not for others.
The first paper insert is a charcoal pocketbook insert by Banditappple. It's slim for just jotting down notes and works well in the front position.
Thanks for looking.