So, to save some money, I bought these used bags that turned out to be very high quality.
Originally, these bags had been installed on a bike by Easy Brackets. They had been installed twice, leaving eight holes in the back of each bag. http://www.easybrackets.com/
I bought Cycle Visions Barebacks to install my new bags, and attempted to use one of the existing holes and drill a new hole to attach the bags. http://www.cyclevisions.com/index.php/cvstore/cv-products/bag-mounting/barebacks.html
Unfortunately, with a rider on my rear seat, the bags were so low that they interfered with my side mounted license plate. So there were nine holes in the back of each bag. Before drilling two new holes, I wanted to patch these up so they would make more sense than carrying my gear in a net.
Step 1: Tools and Materials
1. Super glue - I used Loctite Ultra Gel Control. The gel is nice because it doesn't soak in, it spreads out and covers both sides of your working surface.
2. Scissors - used to cut your leather.
3. X-Acto knife - also used to cut leather.
4. Scrap leather - whatever matches your project, but you really won't need a whole lot.
5. Leather lace - to fill your holes
6. Something round (and larger to your holes) - to use as a template
Step 2: Patch the Inside
I used a circle shape for the patches so the edges wouldn't curl up, be aware of that if you want to cut squares or rectangles.
Lay your template down and cut around it with your knife. You could alternatively score the leather and cut it out with your scissors, whatever is easier.
Lay your patch face-down and put a bead of superglue around the edge.
Press it down against the hole until the glue sets, about fifteen seconds.
Step 3: Plug the Hole
Cut off a length of your leather lace and roll it around itself so it fits into the hole. Basically, the shape of a cinnamon bun.
Press your leather roll into the hole and press down. Use your other hand to press from the opposite side to it doesn't push out.
Step 4: Patch the Outside
After you add you last set of patches, that's it!