Part name and number highly needed

[MBSL560]

Hello,

I went today for oil change and check up and then suddenly the brakes stopped working. They have touched the brake fluid box.
Now they are telling me that the rear tires never received brake fluids!!!!!!!!!!!

I am in need of the name and part number of that metal thing which sits below the brake fluid plastic box. Can I even buy that as single part or is it together with the plastic box? My car is a Mercedes SL 560 from 1987 and american style. The parts are therefore different to the same cars built in other countries.

I had to leave the car back at the shop as I could not use the brakes! That was scary.

I hope you can help. I also took pictures of that part in my car. Please have a look at the whole and the pic as a close up of the metal part.

thanks a bunch!