This is the kit number, but they are expensive, and you get one boot, steel spring and a nut per kit.
http://www.peachparts.com/shopforum/mercedes-parts-reference-library/185269-1165860533-upper-control-arm-ball-joint-boot-kit-w116-123-126-a.html
EBay has a lot of generic tie rod boots and so on but you need to know the dimensions of the arm and ball joint shaft.
Places in the US that I found had no longer available. In the picture you see a white plastic part.
I can only guess what that is for. I did not change the boots I changed the arms. However, when you change even one arm it alters your alinement.
https://www.pelicanparts.com/More_Info/1165860433.htm?pn=116-586-04-33-M22