How much a machine’s manufacturer uses his own produced parts, you can see at his vertical integrations.
The quality and the price of these parts mostly is high, the lifetime of them too. Normally the availability is high too, because machines producer need this parts for their production.
Even if the machines producer did not produce the part by himself, sometimes they put their logo on it. This will be done when they have producing contract with parts producer, stating to buy a big quantity of the part only for the machine’s producer.