As to the authenticity cards - I have a Dior (the "evening version" of the Lady Dior in black with the silver stud things) that my father picked up for me in London, bought at the Dior boutique on Sloane (sp) street (I think that is the name of the street), and it has the authenticiy cards but...... they are not stamped or marked at all by the shop!
I purchased my dior handbags straight from the boutique. The authenticity cards don't even have the stamp on the back. But it is authentic since i purchased it from the store. I guess not all stores would stamp them