Looks like you started from your own mind and not copying, a small hint, cardboard works great for your initial design, its about the right thickness and forms easily, so you can think of something and put it together with cardboard initially, if it seems to work, then use the cardboard as a template, and cut the leather to match and go from there.
I love working in leather, especially holsters and mag pouches. Get a few books, I especially like John Bianchi ( Blue steel and gunleather) some good tips there, especially on finishing the leather.