BGF, the "Appalachian trash" joke wasn't directed at anyone's work; more a comment on our absolute befuddlement at what people want at various times. We could understand copying the various features of a regional style or bags made at a particular period of time, but making a copy that was representative of the current state of a bag left to rot in a barn for 50 years or more was just beyond us. Neither of us could believe it when the copies I made sold. We never imagined some of the things that are in demand today. . . .
As Pathfinder wrote, that is a very simple bag--about as simple as a bag can be. The basic pattern for that bag is like an envelope with the sides cut, then laced up with a running stitch. (I wonder if the maker set the flap off-center to allow easier access to the contents? From the horn attachment, it seems he was right handed.)
You could make one and be sure that it would turn out usable no matter how inexperienced you might be. If you are unsure how to start, take Pathfinder up on his offer. (I wish I'd had an offer like that when I started, my first two bags were unusable, and the third wasn't much better!)