your sort of right, but you have names mixed up.
MB Quart - old stuff, hand made in germany. blue prints where then sold to German Maestro. MBQuart company was then taken over by china, and went to shit. MBQuart older stuff is really good, newer stuff is poor.
German Mestro are using the original mbquart bluprint(the good ones) and are producing them. which are good. there was never a bad German Maestro. but you will find some people with biased opinions as there are different brands that are preffered by different people.
the entry level GM stuff i think may get their parts from china. but why would you want entry level
/csb