don't worry about the value of the camera -- i regularly carry camera gear worth a coupla thousand around -- leica -- and even in san francisco's seamy section never had a problem -- usual care is advised, a closed bag, a strap around your wrist or neck, and so on ... but generally speaking crooks want cameras they can sell easily and old timey gear doesn't match that -- as to damage, cameras are made to be used, a good strap, a padded bag, your camera will be fine. Try not to trip.

worst happens? $400 won't even buy a low-end DSLR but it will buy you another Leica R body.

my preferred bag of choice is an old swiss army gas mask bag. Doesn't look at all worth stealing, and a leica CL looks like a cheap point and shoot.