Thanks all!
The bag was made inside out, stitched all the way around then flipped. The flap is stitched on as well as riveted as per the original bags that I used for inspiration. The "mustang" oiled from Tandy is great, but it is of limited stock. Too bad since its some of the nicest stuff they have. Luckily, I've found a place close by where I should be able to get something comparable.