If it was me I'd CAREFULLY shop for a quality body shop. My father was Navy Sea Bees and learned how to take wrecked vehicles and return them to like new condition when he was in the Navy.

I saw him take cars in much worse condition than your mercedes and with a little elbow grease, make it look like NEW!

Again, you have to carefully vet out the body shop but if they know what they are doing I believe your car could be returned to its former glory.....