I decided to make a new bar bag mount for the 29er. This one is wider and ensures the brake levers sit over the harness rather than the roll bag. It's designed to take a 13 litre dry bar. It might come in handy for holding something. If I do another one though, I will rotate the tabs of the elastic cord 90 degrees around. The eagle eyed amongst you will notice they are in the wrong place. It may come in handy as it is, but it's practical nature is a little limited.
The piping around the outside is a reflective trim.
I will replace the white elastic cord stopper end when I get a black one ordered.