Yes, this is a M119 motor, very different from a 420SEL (126 chassis).
Once you get the front plactic covers off the heads it looks alot easier, then you can take the strips off the top of the valve covers. The wires have a small strap on retainer on the front, it's part of the plastic piece that's under the dist caps, there is also a coil wire from the left side of the car that runs to the right cap.
The caps are each held down by 3 allen screws. Once the caps are off the plastic pieces under the caps can be removed by removing a small assortment of allen head cap screws, but I don't believe these actually need to be removed.
Not sure if your kit will even come with the coil wires.

Gilly