The auxilary fuse box in question (used mainly for the fog lamps) is part number A 000 545 99 01 and it is available at Mercedes, but - it will come in black plastic and without the thumb screw - just click on (this is how it is picture on the drawing in the part list, but perhaps the one with thumb screw is more correct). It is similar to one used for the radio fuses. I think Members here may have one at hand, if not, I saw it it some of the internet stores, but in black plastic, I think. Ebay may work as well.
As for the bracket - discussed many times here, which should be helpful. Part number A 113 545 01 40. I would have thought - Members or ebay if you would want to buy.
I am attaching some pictures form previous threads on this topic.