I don't think anyone is trying to pull your chain. Manufacturer's marks are not on every part. You just don't always know.
As a matter of fact, Just because you see "Timken" on a bearing does not mean it was made by Timken.
The government has been burned more than once by installing knockoff bolts and screws on military products because they got a "good" deal from a "new" supplier.
It happens. The best you can do is try to identify the products you buy. There is no guarantee.