Carbon and soot are the Nemesis of diesel engines but are inherent to their operation.
Your engine doesn't look bad at all, you can expect some. Wish the pics were lighter to reveal if liner cross hatching is present or they are glazed, which contributes to blow-by.
Several things can cause excessive carbon build up: Low operating temperature, late injector timing, dirty air cleaner, and faulty injectors. To name a few.
I think I understand what you mean by “lapping”. You are referring to valve “overlap” which is controlled by the camshaft grind. There is nothing you can do about it, it's engineered into the design.
Account deleted.