How many kilometers/miles on the engine?

I'm cleaning my injectors and swapping the nozzles for new ones on my 200tdi. Out of curiosity, since I don't know how many true kilometers/miles are on my truck (previous owner had no history on it, and probably didn't even change the oil in the 8 years he owned it), so I'm always trying to find signs of how many true miles/kilometers the truck has done.

Here are the pics. Anyone care to take a guess? Bonus points if you explain your rationale for the sake of my education.

Can only see red x for pics , can you upload again

Cut the block in half and count the rings....