So, can you tell us the exact parts that you bought. I see them but do they have names? I really can't tell what the thing on the bottom is. So it looks like 1 rail...2 hooks... and the bottom thing. Did you put grommets on the back side of the rail (inside the pack)? Super cool, and where can you purchase these parts? Thanks for the heads up, I'm planning on doing something similar with equestrian saddle bags (DIY)