brachal
Refrigerated User
I'd say try an army surplus store or two. You can usually find a variety of well-made bags for very little money. I can think of a couple of gas mask pouches I've had that probably fit what you're looking for. I also like the fact that they don't scream camera bag. My go-to small bag is a British army '37 pattern small pack with shoulder strap ... $5. If I'm worried about padding, I stuff a small towel from the bottom up the back -- instant padded compartment.