Siemens EQ5 motor brushes - other wearing parts?

Hello,

I have identified the problem with our "no longer grinds" machine: the motor carbons are down and otherwise it is unblemished to unremarkable.

I have three questions
:-Source of supply?
-Do you have instructions for installation? Apparently, the two carbons are also different lengths and would therefore have to be distinguished.
-Which other maintenance / wear part errors could be done at the same time, if you have the machine anyway so far open?

So far I have only found one source on ebay. The coals are replicas and the coal dust ends up yes partly in the coffee and thus in the body. Do you guys think this is safe and would buy the cheapest? I would at least like to know how much more expensive original or branded would be....

Thank you, selch

Hello, here is a source of supply, I have already installed several times.
https://www.kaffee-optimal.de/motorkohlen-kohlebuersten-kohlen-fuer-bosch-vero-mahlwerksmotor/
I would only replace the carbons....never touch a running system.
Instructions for disassembling the machine there are enough on Youtube.