Something to consider- leather is durable in one way, against abrasion and extreme heat, but not durable in another way, against prolonged moisture. It mildews and rots if it's exposed to humid climates. Cordura and ballistic nylon don't have that problem, and to boot are lighter and more available in ready made bags, easier to sew if you go that route, and less likely to stand out. Good luck with the new bag, whichever way you go with it.