I will step in but others may have better info. My guess is that it is not leather, it likely is reconstited leather (think particle board instead of plywood). The stuff is not strong and does not last, but in the store is hard to tell apart. Any stitching you do will likely tear out too. If the front piece is actual leather than you could open up the piece and replace the end piece that is damaged.You can use almost any material, since you can barely see it. Matching can be tough.
On the wear spots, i would just use a leather conditioner on the total sofa and deal with the wear. Old leather= character.
Aaron