Hi Paul,
Let us know how you get on at your local M-Benz dealer.
Last year I asked my local dealer in Cardiff, they said they were unable to help me, and suggested I try the local locksmiths.
We have three really specialist locksmiths here, and only one was able to help,
he recognise the pattern from his pattern books and ordered & cut the blanks I previously mentioned for £10.
Thinking of you, I passed his shop today, but Unfortunatly, I think he is no longer trading.
Good luck
Paul