Wow, that looks like a Gerard Darel. Someone posted a while back about a Tano bag (not sure if it was this one or not) that also looked like a Gerard Darel bag. She had to return it b/c it was huge!! Not sure of the dimensions on this one.
I have the Loveboat which I believe is very similar (looks the same, but the dimensions are a bit smaller, still a large bag though). I wear it on my shoulder all the time. The handles are short, but it works for me. I'm 5'5" and 120ish. HTH, good luck!