Thanks for your patience all. Finally had time to get the lights fitted...and thankfully it wasn't as much of a headache as I anticipated(my biggest concern was how the Nolden stainless adapter ring would fit and affect the aiming of the lights).
Their stainless adapter ring works very well(they have an adapter ring specific for G's as these 7" round lights are also used on other applications like Rover, Jeep, VW, etc). I didn't use their supplied round white insert clips(for the ball socket adjuster screws) for the adapter ring. Eventually, after figuring out with the first lamp that I wouldn't need to use their white clips, I just popped the 3 black clips(circled in green in picture below) out of the factory headlight and then moved the entire black plastic "bucket" w/ 2 headlight adjusting screws and 1 mounting stud from the factory Mercedes light onto the Nolden adapter ring and light. This way the aiming wasn't affected. I double checked the aiming of course.

The biggest hurdle was securing the factory Mercedes rubber headlight trim rings--these fit around the very edge of the headlights so that when the body-colored headlight surrounds(left and right of center grille) are re-fitted, there is no gap between them and the light itself. I ended up using gaffers tape to secure the rubber rings to the backside edge of the body-colored headlight surround as they are just a tad bit too large to fit securely on the Nolden's.
Lighting output and cutoff pattern is excellent. There is a very distinct cutoff line. The bottom "halo" (circled in green in picture) will take some getting used to, but I assume this is present because of the parabolic "eye" in the headlight.
Nolden LED on left side, factory Mercedes/ZKW H7 halogen w/ PIAA NightTech bulbs on right; LOW BEAM(yes, I know I was too close to the door but I was just using it as a before/after line of reference using the masking tape, as my OEM lights were already aimed correctly);
HIGH BEAM;
One small issue I have is the wiring for the position light wiring. Their connector is a very high quality "weatherpack" connector whereas the Mercedes factory uses a lower quality blade-style connector. I have not adapted their wiring to the Mercedes blade-style connector as their wiring lead talks about warranty being void if tampered with, so I'm waiting to hear from them on what they'd like me to do. I'd rather modify the light vs the truck in case someone wants to go back to OEM halogen's for some reason.
Nolden vs OEM;
Nolden's;
I haven't driven much at night with them yet but from the small amount of driving I've done, the clarity of light is much appreciated. We'll see how it does in the Oregon rain.