Looks like there is a recess in the intake adjacent to the socket of the rod going to the venturi. Could that be the alignment spot? I have a 220SE engine, but is a Ponton. The pump is basically the same but the linkage system is very different. I do recall that in the service manual (starting 1959), there is extensive information on your injection system. May need to get that.
Like Joe said, the concepts of the adjustment are the same, but none of the actual dimensions are. Because this site is SL113, it covers the SL cars in detail. Some information is similar to the W111 cars and you have to sort that out. For whatever reason, there are no sites for W111 cars that are as well organized and extensive as this site. If you plan on working on the car yourself, the service manual will be your best friend.