You should be able to order new tumblers that match your VIN from the MB dealer. I had to order a new tumbler for the driver's door on my 190E a couple of years ago and all I had to do was go to the parts department with my VIN and they were able to order it. I took the broken one out, put the new one in, and it is good as new. I know you mentioned that your vehicle is a 380SL, but I would think that you should be able to buy just the tumblers instead of the entire door handle for each side.