You need the vin and title or registration. The dealer doesn't make the keys they order them, from Germany.(
afaik) MB's use laser cut steel keys, brass keys will ruin your locks. I think I paid about $20 each last time I had a set made. I need to get a set made next month for my SD.
I had keys made for my SDL when it was un registered. I had the title that was it, it is really a simple thing to do.