there is plenty of places that shotpeen,just make sure they dont farm the work out or it will cost more.
samQ yes your mising something!like a balancing machine.sure you can take metal off to get all the same weight but the weight you take off will not be in the right place for a rotating assembly.be like putting weights onto a wheel were ever you felt like it,wouldnt balance it would it.confucius say"to balance something that turns, you must first spin to find were it is unbalanced"lol it wasnt confucius, it is really my saying but sounded better.
mick