Or that your brush holder hasn't been arcing against the motor's rear cap so hard there are now craters of missing aluminum in the area the two make contact...make sure you armature is not melted down before dumping money into it.
I sure hope the arameture copper brush area was not reinstalled looking like that. New brushes will not last long with that eating them up. Also those gaps in the comutater needs to be cleaned out too. Usually this kind of work is done on a lathe.
having lived and worked in mainland China, I can definitely attest there is a wide variance of quality when it comes to anything they produce. If you want it cheap, they'll spec/build/sell it to you cheap. If you want quality, they will spec/build/sell it to you with an according price tag. want cheap? you'll find it at the dollar store. want quality? you'll need to shop elsewhere. As consumers, most Americans have no grasp on that concept.I grew up most my young life across the Atlantic Having locally made parts with pride was not an issue what so ever , It was a treat to have some parts imported to us that was MADE IN USA as it was quality reputable parts .Latter on i moved to this great nation over 25 years ago and witnessed the major go down hill fast market with it's Parts majority made in cheep low quality China . Now its the other way around when i need parts ..world if you ask me .
It took me over a week to locate an GKN CV joint for the TDI VW , But you could pick one up and get the 2nd one for free at the local parts store if you need a Chinese one