You are missing the specs the shop manual says are important....and how to insure you have them....
You are missing the amount of blowby the manual says is ok... and how that blowby should be measured.
You are missing the rebuilding concepts built into the design of the engine which would dictate little things like that if you need new rings and have the engine opened up THAT far... that you probably should press in new bores and that each piston would need to be measured in order to hone the new bore to the correct size required to meet the very close specs which MB considers necessary for a long lasting engine...
ETC...

Shop manual = cheap insurance ( and good cold weather reading ).