How about Dior Saddle or Street Chic? They have in messenger style. Dior Copacobana is also a messenger bag, but it has logo. Here's the pic of messenger saddle and street chic... Oh, this pic is pic of my whole diors - sorry don't have the pics for each of them alone (in the meantime)... the saddle messenger is the big brown (chocolate) one and the street chic is the one in dark brown colour - behind the purple bowler or next to the copacobana. Dior stores may still have them, or stores like NM etc or even Elux.
Those Diors are daytime bags thou... good wear when I have to catch my 2 years old baby when she runs at the mall

. Btw, are you looking for daytime or nite bag? For nite, chanel has some cute sling bags.