A video from M/B diesel channel on changing spark plugs. They must have covered every possible repair on a diesel and moved on.
Had a Ford four cyl. with 8 spark plugs. I even had a Mazda rotary with 2 distributors. I forget if it had 4 spark plugs 2 from each distributor, but I do remember setting the points was a real PITA. I wish I had Youtube back in the late seventies maybe I would have learned an easier way to set those points.