All good points John, which brings me to another point. Everyone wants pictures today. If you offer a spark plug for sale they want a picture of it.
Even with a picture, not everyone will see things that are hiding in clear view. I the case of said picture of the cam shaft, I knew the problem was going to be on the cam because that's what the picture is showing you - a cam shaft. The problem cam lobe in the picture is the fourth one from the end of the cam shaft. This is the lobe that runs the intake valve on number 5 cylinder. I guess someone could go back and circle the place on the picture where they want everyone to look.
If it was not pointed out that something was wrong in the picture I doubt very much I would have seen it. If I was working on the car myself I would have seen it because I look for things like that. I would have caught it during the valve lash adjustments anyway. It takes years of expirience to spot little things like this, this one being one of many to look for.
I guess without pictures no one will figure out what was wrong with the 190SL engine. In this case, the main bearings were installed upside down. The hole from the main oil galley was completely blocked off so that number 1 and number 3 main bearing wasn't getting any oil pressure. The center thrust bearing was OK because was installed properly and number 2 and number 3 rod bearings were also OK because they were getting oil pressure fed through the crank shaft. Number 1 and number 4 connecting rod bearings were damaged because no oil was flowing through the crank from the blocked main bearings.
Had I drove this car, it would have siezed up with a lot more damage than scuffed bearings. Figuring out what went wrong is all part of the repair.