Mike,
that info on surface finishes was wrong. I think even the BEST high RPM CNC milling machine is going to have a tough time getting as good a surface finish as a mediocre surface grinder..

Segmented wheels? Not sure where this guy gets his info? Maybe on a Blanchard grinder which is a bit of a dinosaur. Any decent reciprocating grinder will give you a better finish than milling...

Sounds like your engine is in good hands