One caveat to keep in mind:
I am also a leather worker (and metal, including silver smithing) and have several of those exact same cases (dad is a retired USAF Colonel, they are big with officer types) and you will find that most of the material used to manufacture those is in fact a sandwich of very thin leather outer layers, with a cheap cardboard inner layer. The "leather" can tear and rip along the stitch line if you aren't careful, and the layers will come apart as well.
I believe the only portion that is actually solid leather is the top and side flaps and the side gussets.
Best of luck, and kudos for making your own gear!