hey Alex

The mixture screw is like 10 bucks at carriage house NL, but I bet Phil at mercedesshop will get it to you cheaper, I know you will have to die-grind the mixture rivets out and Im not sure how the new one bolts up? make sure there is no leaks,
I got the my manuals off of ebay used for 120, for the engine
102 and chassis,(stacked on top of each other is 6-7 inchs of reading) they have extra chapters just for the differnet
16v's , Ask the dealer for the shop book thay have them there

hope this helps
Dave